Official White House Photo by Shealah CraigheadBy LIBBY CATHEY, ABC News

(WASHINGTON) -- The government's top infectious disease expert, Dr. Anthony Fauci, is expected to warn senators in a videoconference hearing Tuesday that there will be "needless suffering and death" if the country opens up too soon, according to an email Fauci sent the New York Times.

His testimony comes after President Donald Trump on Monday exaggerated the availability of coronavirus testing in the U.S. on Tuesday in his push to reopen the country, claiming Americans returning to work can get tested daily "very soon," even though many governors disagree.

Our Testing is the BEST in the World, by FAR! Numbers are coming down in most parts of our Country, which wants to open and get going again. It is happening, safely!
— Donald J. Trump (@realDonaldTrump) May 12, 2020

The Senate hearing this morning is the first time Fauci will testify since mid-March, and Democrats note he will be outside the presence of Trump.

He is testifying -- along with some of the most prominent doctors on the president's coronavirus task force -- Centers for Disease Control and Prevention Director Robert Redfield, Food and Drug Administration Commissioner Stephen Hahn and coronavirus testing coordinator Adm. Brett Giroir -- in the historic hearing before the Senate Health Education, Labor and Pensions Committee to field questions surrounding reopening the economy, as more states lift restrictions meant to slow the spread of the virus.

Three of the four witnesses -- Fauci, Redfield and Hahn -- are in some form of self-quarantine following "low risk" contact with at least one infected White House staff member. Even the committee chair, Sen. Lamar Alexander, R-Tenn., will preside from his home state after one of his staff members, too, tested positive for the contagious pathogen.

The teleconference testimony comes as precautions are being put in place at the White House over fears the virus has invaded the West Wing, including a mandate that staffers must wear masks following positive coronavirus tests from one of the president's valets and the vice president's press secretary.

Here are Tuesday's most significant developments in Washington:

Here is how the Senate hearing is unfolding. Please refresh for updates.

1:15 p.m. All four witnesses say they do not have a confrontational relationship with Trump

Before the hearing ended at 1:30 p.m., Sen. Kelly Loeffler, a Georgia Republican, asked each of the witnesses to characterize their relationship with President Trump and all four said there was no confrontational relationship whatsoever and that they could speak freely.

“There is certainly not a confrontational relationship between me and the president, as I mentioned many times,” Fauci answered first. “I give advice and opinions based on evidence-based scientific information. He haers that. He respects it. He gets opinions from a variety of other people, but in no way, in my experience over the last several months, has there been any confrontational relationship between us.”

Redfield, Hahn and Giroir echoed their colleague.

“I’ve always felt free to give the best public health advice that I think needs to be given at the time," Redfield added.

“I do not have a confrontational relationship -- had not had a confrontation relationship with the president,” Hahn said. “He asks questions. I have given him my honest answers rooted in data and science, and he has listened respectfully to those Incorporating that into his decision making.”

Finally, Giroir said that the entire group have a close working relationship and included a shout-out to coronavirus response coordinator Dr. Deborah Birx.

“We work very closely together -- all the scientists, all the physicians,” Giroir added. “We have a very productive working relationship with each other and also with the president and vice-president. It would not be confrontational. I firmly feel that we have the ability to honestly state our opinions and recommendations. That's been that way since the beginning.”

12:55 p.m. Romney says US testing record 'nothing to celebrate whatsoever’

Utah Sen. Mitt Romney, the only Republican to vote for the conviction of President Trump in his impeachment trial earlier this year, began his remarks with a thinly-veiled criticism of Adm. Giroir, who is overseeing the administration's testing efforts.

“I understand the politicians are going to frame data in a way that's most positive politically -- of course I don't expect that from admirals -- but yesterday you celebrated that we had done more tests and more tests per capita even in South Korea, but you ignored the fact that they accomplished theirs at the beginning of the outbreak,” Romney said, adding that while the U.S. “treaded water during February and March,” South Korea was conducting robust testing.

“Partially, as a result of that, they have 256 deaths and we have almost 80,000 deaths. I find our testing record nothing to celebrate whatsoever. The fact is, they're test numbers are going down, down, down, down now because they don't have the kind of outbreak we have. Ours are growing up," Romney said. “I think that's an important lesson for us as we think about the future.”

Romney then asked Fauci if former President Barack Obama or President Trump have done anything to delay a coronavirus vaccine, after Trump has claimed for months that his predecessor left him without the tools to fight the virus.

“No, no, not at all,” Fauci said. “Certainly, President Obama nor President Trump are responsible for not having a vaccine.”

12:07 p.m. Fauci tells Warren that virus isn’t ‘completely under control’

Pointing out that Fauci has advised six presidents and battled deadly viruses for his entire career, Sen. Elizabeth Warren, D-Mass., asked him point-blank: “Do we have the coronavirus contained?”

“It depends on what you mean by containment. If you think that we have it completely under control, we don't,” Fauci said. “If you look at the dynamics of the outbreak, we are seeing a diminution of hospitalizations and infections in some places, such as in New York City, which has plateaued and started to come down the wall ends, but in other parts of the country, you're seeing spikes.”

“I think we're going in the right direction, but the right direction does not mean we have by any means total control of this outbreak,” he added.

Warren also asked Fauci about the severity of the virus returning in the fall, as he has previously warned will happen, to which Fauci said it all depends on how they prepare for it now.

“If we do not respond in an adequate way, when the fall comes, given that it is without a doubt that there will be infections that will be in the community, then we run the risk of having a resurgence. I would hope by that point in time, in the fall, that we have more than enough to respond adequately. But if we don't, there will be problems,” Fauci said.

11:55 a.m. Murphy presses witnesses on whereabouts of additional CDC guidance on reopening

Sen. Murphy, D-Conn., first asked the witnesses if they were taking salary, to which they all replied yes, before Murphy used it as an example of income inequality amid the coronavirus outbreak, which he argued the federal government should be helping with.

“Quarantine is relatively easy for people like you and me. We can still work and get paid, but there are millions of other Americans who work jobs that can't be performed from home or are paid by the hour,” Murphy said.

“It's just remarkable to me that this administration has not yet developed a mechanism for states to implement and pay for a quarantine system that will work for all Americans. Your plan to reopen America requires states to develop that plan and yet my state has no clue how to implement and pay for that system without help from the federal government,” he said.

Murphy prefaced his second question by saying, “I worry that you're trying to have it both ways. You say this state shouldn't open too early. But then you don't give us the resources to succeed.”

The senator went on to question when follow up guidance to the White House’s reopening guidelines would be released by the CDC, adding, “My state needs it. We don't have all of the experts that you have and so we rely on you.”

Redfield said new guidance would go online “soon.” Murphy said that “isn’t very helpful” as states are already reopening.

"We’re reopening in Connecticut in five days, in 10 days -- this guidance isn't going to be useful to us in two weeks," Murphy said.

11:35 a.m. Fauci turns Paul’s argument on humility around on the senator

GOP Sen. Rand Paul, R-Ky., used his question time to suggest kids suffering less from coronavirus means schools should reopen and that the U.S. should consider following Sweden's model of no mitigation.

“I think the one-size-fits-all, that we’re gonna have a national strategy and nobody is going to go to school is kind of ridiculous,” Paul said. “I think they will have a little bit of humility and our belief that we know what's best for the economy and, as much as I respect you, Dr. Fauci, I don't think you are the end-all.”

In a rare move, Fauci asked to respond to the senator with only 32 seconds left on the clock, first by thanking Paul for his comments.

“I have never made myself out to be the end-all, and only voice, in this. I'm a scientist, a physician and a public health official, I give advice, according to the best scientific evidence. There are a number of other people who come into that and give advice that are more related to the things that you spoke about the need to get the country back open again and economically. I don't give advice about economic things. I don't get advice about anything other than public health," Fauci said.

"The second thing is that you use the word we should be ‘humble’ about what we don't know. And I think that falls under the fact that we don't know everything about this virus, and we really better be very careful, particularly when it comes to children, because the more and more we learn, we're seeing things about what this virus can do that we didn't see from the studies in China, or in Europe," Fauci cautioned the senator.

"We've got to be careful, if we are not cavalier, in thinking that children are completely immune to the deleterious effects," he added. "I am very careful and hopefully humble in knowing that I don't know everything about this disease, and that's why I'm very reserved in making broad predictions."

11:30 a.m. Fauci warns reopening too soon could lead to even worse outbreaks and economic fallout

Sen. Bob Casey, D-Penn., asked Fauci to repeat concerns that he touched on in Sen. Patty Murray’s earlier questioning, and he again said that while he understands the push to reopen, he said some areas run the risk of triggering an even worse outbreak -- with worse economic impacts.

“My concern is that as states or cities or regions, their attempt -- understandable -- to get back to some form of normality, disregards to a greater or lesser degree the checkpoints that we put in our guidelines, about when it is safe to seed and pulling back on mitigation,” Fauci said.

“If that occurs, there is a real risk that you will trigger an outbreak that you might not be able to control -- which in fact will set you back, not only leading to some suffering and death that could be avoided, but could even set you back and almost turn the clock back rather than going forward,” he testified.

11:15 a.m. Fauci says death toll likely higher than what's been reported

In questioning by Sen. Bernie Sanders, I-Vt., Fauci revealed his belief, along with many of his colleagues, that the COVID-19 death toll is probably higher than what's been reported.

"Most of us figure the number of deaths is likely higher. Given the situation, particularly in New York City, when they were really strapped with a very serious challenge to their health care system, there may have been people who died at home who did have COVID who were not counted as COVID, because they never really got to the hospital," Fauci said.

"I think you are correct that the number is likely higher. I don't know exactly how much higher, but almost certainly higher," he said.

11 a.m. Fauci: If guidelines not followed, 'the consequences could be really serious'

Alexander's first question to Fauci is what he would advise the chancellor of the University of Tennessee as schools grapple with the decision to return in the fall.

"I would tell her," Fauci said, "that in this case, that the idea of having treatments available, or a vaccine, to facilitate the re-entry of students into the fall term would be something that would be a bit of a bridge too far."

Fauci went on to say that it would be a different situation if a vaccine was already available.

"If this were a situation where we had a vaccine, that would really be the end of that issue in a positive way. But as I mentioned in my opening remarks, even at the top speed we're going, we don't see a vaccine playing in the ability of individuals to get back to school this term," Fauci said.

Dr. Anthony Fauci says the idea of having treatments or a vaccine as students begin school is “a bit of a bridge too far.”

“Even at the top speed we’re going, we don’t see a vaccine playing in the ability of individuals going back to school this term.” https://t.co/kkPwJwwPSU pic.twitter.com/yx7IqcUIxS
— ABC News Politics (@ABCPolitics) May 12, 2020

Murray brought up Fauci's warning of "needless suffering and death" if the country opens too soon, in her first question, asking the doctor what is his most important message for communities and states that may be reopening too soon.

"I get concerned if you have a situation where the dynamics of an outbreak in an area are such that you are not seeing that gradual 14-day decrease that would allow you to go to phase one," Fauci said, pointing to the White House guidelines on reopening and a "gating criteria" that is not being followed in certain areas. "When you jump over those various checkpoints and prematurely open up, without having the capability of being able to respond effectively, my concern is that we'll start to see little spikes that might turn into outbreaks."

Fauci went on to say that if a community doesn’t go by the White House guidelines, “the consequences could be really serious.”

“There is no doubt, even under the best of circumstances, when you pull back on mitigation, you will see some cases appear,” Fauci said. “It's the ability and the capability of responding to those cases with good identification, isolation, and contact tracing, to determine whether you can continue to go forward as you try to reopen America -- so it's not only doing it at the appropriate time, with the appropriate constraints, but having in place the capability of responding when the inevitable return of infections occur.”

Dr. Anthony Fauci says that if states “prematurely open up without having the capability of being able to respond effectively and efficiently” to COVID-19, his “concern is that we start to see little spikes that turn into outbreaks.” https://t.co/kkPwJwwPSU pic.twitter.com/Mzap8Hi0O5
— ABC News Politics (@ABCPolitics) May 12, 2020

Based on ABC News latest analysis, no states currently easing restrictions have seen a decline in cases for 14 days in a row, as the White House guidelines dictate they should before moving onto "phase one" of reopening.

10:35 a.m. Fauci warns of the unknown efficacy of vaccine candidates in opening statement

Fauci outlined the goals of the NIH in addressing the pandemic and, ever cautious, offered a word of warning as the world waits for a safe coronavirus vaccine.

“The strategic plan that we have is four-fold. One, to improve our fundamental knowledge of the virus and the disease it causes. Next, to develop new point-of-care diagnostics. Next, to characterize and test therapeutics. And finally, develop safe and effective vaccines,” Fauci said, adding that there are “at least eight candidate COVID-19 vaccines” currently in clinical development.

“I must warn that there's also the possibility of negative consequences, where certain vaccines can actually enhance the negative effect of the infection,” he added. “The big unknown is efficacy.”

10:25 a.m. Top Democrat Sen. Murray says public 'counting on us for the truth'

In her opening statement, Ranking Member Sen. Patty Murray, D-Wash., questioned whether President Trump was telling the truth about the government's response, and while she said agreed with Alexander’s call for ramped-up testing, she said "testing along won't be enough to reopen our country."

“I'd like to thank, not only our witnesses for joining us today, but also our committee staff are working to set up a safe format for members and witnesses, and the public to participate in this hearing remotely families across the country are counting on us for the truth about the COVID-19 pandemic. Especially since it is clear they will not get it from President Trump,” Murray began. “Lives are at stake.”

Murray ticked through a list of what she called “delays” and “missteps” by the administration such as allowing inaccurate antibody tests to flood the market and falling behind on outbreaks at meatpacking plants and nursing homes.

“We recently learned that after experts at the Centers for Disease Control and Prevention spent weeks, developing a detailed guide to help our communities understand how to safely reopen when the time comes, the Trump administration tossed it in the trash bin for being too prescriptive,” she added.

10:10 a.m. Sen. Alexander begins hearing from Tennessee home

The Senate Health, Education, Labor and Pensions Committee Chair GOP Sen. Lamar Alexander of Tennessee, in his opening statement Tuesday morning, kicked off the historic video conference hearing with an emphasis on coronavirus testing and an acknowledgement that it currently falls short.

"Vaccines and treatments are the ultimate solutions, but until we have them, all roads back to work and back to school go through testing. The more tests we conduct, the better we can identify the small number of those who are sick and track those who they have had contact with," he said. "Then we can quarantine the sick and exposed instead of trying to quarantine the entire country with disastrous effects on our economic wellbeing,” Alexander said. “That's why I said last Thursday, what our country has done so far in testing is impressive, but not nearly enough.”

“Staying at home indefinitely is not a solution to this pandemic. There is not enough money available to help all of those by hurt, by a closed economy,” Sen. Lamar Alexander says, adding “all roads back to work ... lead through testing" and vaccines. https://t.co/kkPwJwwPSU pic.twitter.com/w7j99E1Dmv
— ABC News Politics (@ABCPolitics) May 12, 2020

Trump and Pence to maintain distance from each other

President Donald Trump and Vice President Mike Pence will maintain distance from each other in the immediate future, according to a senior administration official.

The decision was made in consultation with the medical unit at the White House.

It comes after Pence, though present in Washington, was notably not in attendance at Trump's briefing Monday in the Rose Garden.

ABC News' Katherine Faulders

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