The nation’s top health officials warned Tuesday that the United States risks new coronavirus outbreaks and possibly a broad resurgence nationwide if states and cities reopen too quickly, setting up a potential conflict with President Trump and his deepening view that the country must lift restrictions and spark the moribund economy.

Anthony S. Fauci, the nation’s top infectious disease expert, predicted Americans would experience “suffering and death that could be avoided,” as well as additional economic damage, if states ignore federal guidelines, including delaying reopening of most businesses until they see dramatic declines in cases.

Most states already are ignoring at least some of the federal guidelines

. Pennsylvania, where Trump announced he will travel this week for an event meant to cheer on economic revitalization, is among states Trump says are moving too slowly.

“If some areas, cities, states or what-have-you, jump over those various checkpoints and prematurely open up without having the capability of being able to respond effectively and efficiently, my concern is that we will start to see little spikes that might turn into outbreaks,” said Fauci, director of the National Institute of Allergy and Infectious Diseases. “I have been very clear in my message — to try, to the best extent possible, to go by the guidelines, which have been very well thought-out and very well-delineated.”

Also Tuesday, House Democrats unveiled a coronavirus rescue bill that would direct more than $3 trillion to state and local governments, health-care systems, a second round of stimulus checks and a range of other priorities. Republicans rejected the legislation before they saw it.

House bill would add funding for the Post Office

And the White House instituted new restrictions internally, with Trump and Vice President Pence for the time being likely to keep away from each other, White House press secretary Kayleigh McEnany confirmed Tuesday. Two people in Trump’s and Pence’s orbits tested positive in recent days, and most White House officials will be asked to wear masks or face coverings in public spaces.

In his first congressional testimony since Trump declared the coronavirus pandemic a national emergency on March 13, Fauci bluntly laid out the dangers of ignoring federal reopening guidelines. Rather than the small “flare-ups” that Trump said last week might be an inevitable cost of reopening, Fauci warned that the virus could again spread largely unimpeded.

Sens. Tim Kaine (D-Va.) and Richard Burr (R-N.C.) greet each other with an elbow bump before Tuesday’s hearing.

Fauci and two federal government colleagues cautioned that neither a vaccine nor surefire treatments would be available when schools are slated to reopen in the fall — a grim reminder that it is unlikely life will soon return to normal even if Americans try to resume their routines.

Fauci also contradicted Trump’s claims of last week that the virus would die out of its own accord — without a vaccine — and said the true U.S. death toll is probably higher than the 80,000 tallied by Tuesday morning. The total rose above 81,000 later in the day, with the daily death count again rising above 1,500 nationwide.

“That is just not going to happen,” Fauci said Tuesday of a possible sudden end to the crisis. “It’s a highly transmissible virus. It is likely there will be virus somewhere on this planet that will likely get back to us.”

Trump tweeted about his “Transition to Greatness” economic plan but stayed out of public view Tuesday. He announced a visit to Allentown in eastern Pennsylvania, where he is expected to visit medical manufacturing firm Owens and Minor.

Trump has been critical of Pennsylvania’s Democratic governor, Tom Wolf, who began lifting some stay-at-home limits this month. Pennsylvania is a swing state Trump hopes to win in November in a reelection bid imperiled by recession and soaring unemployment linked to the pandemic.

“If you look at Pennsylvania as an example, if you look at various other states, I won’t get into them, the people want to go back,” Trump said Monday. “The numbers are getting to a point where they can, and there just seems to be no effort on certain blue states to get back into gear, and the people aren’t going to stand for it. They want our country open. I want our country open, too; I want it open safely, but I want it open.”

McEnany played down any disconnect between the guidelines developed by Fauci and others as part of a White House task force. The guidelines call for strict controls on movement and commerce at least until states chart two weeks of declining cases, a benchmark few have yet met.

White House press secretary Kayleigh McEnany speaks during a news briefing in the White House on Tuesday.

Trump “has encouraged states to follow the guidelines. That’s still consistently our recommendation today, that you should follow the phased approach to reopening as outlined in the data” McEnany said.

“I do want to stress, as the president has stressed, that we do want to reopen this country.”

Takeaways from the Senate coronavirus hearing

Fauci’s comments came during a contentious Senate hearing as lawmakers of both parties pressed him and other federal health officials on whether the country is ready to reopen. The panel’s chairman and all four witnesses appeared remotely because they all recently came into contact with people with confirmed infections — a testament to how the virus has transformed life even within Washington’s corridors of power.

Sen. Lamar Alexander (R-Tenn.), chairman of the Senate Health, Education, Labor and Pensions Committee, which held the hearing, is self-isolating at home after a staff member tested positive for the virus. Fauci; Stephen Hahn, head of the Food and Drug Administration; Robert Redfield, director of the Centers for Disease Control and Prevention; and Brett Giroir, an assistant secretary in the Department of Health and Human Services, all testified remotely after coming into contact with a White House aide who tested positive.

The health officials also warned that a surge of cases in the fall could be especially challenging, when a coronavirus outbreak could coincide with flu season — in contrast to the president’s statements that the fall season would not be worse.

Redfield said the United States would need a five- to tenfold increase in its capability to conduct contact tracing by the fall to identify all the known contacts of someone who tests positive for the novel coronavirus to prevent an outbreak. He warned that individuals need to remain vigilant in practicing social distancing measures for the next several months.

The hearing often became combative, with Democrats criticizing Trump’s response to the pandemic and even Sen. Mitt Romney (R-Utah) scolding Giroir at one point for politicizing testing numbers. Romney said Giroir “celebrated” the fact that the country is conducting more tests per capita than South Korea in a Rose Garden news conference on Monday but ignored the fact that South Korea had far greater testing capacity than the United States at the beginning of its outbreak.

“I find our testing record nothing to celebrate whatsoever,” Romney said.

McEnany returned to the South Korea comparison Tuesday, saying every U.S. state is in a better position than South Korea.