The U.S. death toll from the coronavirus surpassed 51,000 on Friday, more than a quarter of all the virus-related deaths reported worldwide and quickly approaching the number of Americans – 58,200 – who died during the Vietnam War.

The number of virus deaths is expected to continue to climb, with both confirmed cases and deaths growing in a number of states even as hot spots such as New York appear to have plateaued. Experts have said that confirmed cases and deaths are probably underestimated because of limited testing. As of Friday evening, there were more than 897,000 confirmed cases nationwide – more than the population of San Francisco, or about one in every 370 Americans.

President Trump said Friday that he expects the total number of U.S. deaths, once the pandemic has abated, to be “hopefully far below” early minimum estimates of 100,000.

“I think we’ve done a great job” in addressing the crisis, he said. “I’m not looking for credit for myself, but I am looking for credit for people in the federal government that have done such a great job, and for the doctors and nurses and everybody else.”

In an abbreviated White House briefing at which he took no questions, Trump said Friday that there had been “very, very significant progress” in slowing the progression of infections. “Eighteen states now show a decline in the number of positive tests in the last seven days,” he said. Trump noted that “half of the states have taken steps” or announced plans to reopen sectors of their economies. “It’s very exciting to see.”

In comments after he signed a new $484 billion spending bill with money for small businesses, hospitals and testing to battle the virus, Trump said he was speaking “sarcastically” to reporters “just to see what would happen” when he suggested Thursday that disinfectants could be ingested or injected inside the body to kill the virus.

His initial remarks followed a briefing on studies that indicate heat, humidity and sunlight might reduce the life span of the virus and that disinfectant can kill it quickly on hard surfaces. The president’s suggestion sparked a worldwide reaction.

Appearing to be speaking to medical experts accompanying him rather than to reporters, Trump had asked whether disinfectant could be used “like by injection inside, or almost a cleaning? Because you see (the virus) gets inside the lungs and it does a tremendous number on the lungs, so it would be interesting to check that.”

Medical professionals and other governments on Friday quickly warned their citizens against internal use of toxic disinfectants, as did companies that produce those products.

U.S. Surgeon General Jerome Adams cautioned against prescribing one’s own treatments, urging Americans in a tweet to “PLEASE always talk to your health provider first before administering any treatment/medication to yourself or a loved one.”

Senate Minority Leader Charles Schumer, D-N.Y., speaking on NPR, referred to Trump as a “quack medicine salesman.”

In Britain, a government spokesman said that nation’s approach is driven by science and medical advice: “We can only speak for the U.K. response, and in relation to disinfectant I’m certainly not aware that is anything that is being recommended.”

White House press secretary Kayleigh McEnany accused the media of taking Trump’s comments out of context.

Also on Friday, the Food and Drug Administration warned people against taking the anti-malaria drugs chloroquine and hydroxychloroquine to treat the virus outside of a hospital or formal clinical trial, citing reports of “serious heart rhythm problems.” The agency said some deaths had been reported.

Trump, relying on anecdotal reports, had repeatedly touted the drugs as a “game changer” for coronavirus treatment. His recommendation resulted in shortages for other, prescribed uses of the drugs, even as medical experts had said there was no proof they were effective and safe in treating the coronavirus.

In the wake of this week’s passage of new virus-related spending, House Democrats said they plan to move quickly on a new virus relief package, but Senate Republicans are starkly divided about how to proceed.

With spending on aid for hard-hit city and state budgets, Senate Majority Leader Mitch McConnell, R-Ky., said this week that lawmakers need “to push the pause button” on additional federal spending. He advocated letting states seek bankruptcy protection rather than giving them “free money.”

In a news conference Friday, House Speaker Nancy Pelosi, D-Calif., said “there will not be a bill without state and local” aid. She vowed that “there will be a bill, and it will be expensive.”

New York Gov. Andrew Cuomo, a Democrat, called McConnell’s remarks “dumb,” and Maryland Gov. Larry Hogan, a Republican, predicted that the majority leader would “regret” allowing states to become insolvent during a crisis.

New Jersey Gov. Phil Murphy, a Democrat, said Treasury Department restrictions on how states can spend federal aid have been so tight that his state might have to return some of the funds.

“I was assured this funding would be able to be used flexibly by states, filling holes we now must deal with,” Murphy said. “Those assurances were apparently empty.”

Among other restrictions, the U.S. government has said states and large cities cannot use the money for Medicaid or employees whose work duties “are not substantially dedicated to mitigating or responding to the COVID-19 public health emergency.”

Shannon Stafford styles the hair of Ebony Housey at Stafford’s salon on Friday in Savannah, Ga. Gov. Brian Kemp announced this week the resumption of elective medical procedures, as well as the reopening of certain close-contact businesses like gyms, barbershops and tattoo parlors. Russ Bynum/Associated Press

As barbershops and hair salons in Georgia began to reopen Friday under a controversial easing of restrictions ordered by Gov. Brian Kemp, a Republican, other states and countries faced similar controversies as they tried to balance economic and social demands with health fears.

In Michigan, which has reported 36,641 confirmed coronavirus cases and 3,085 deaths, Gov. Gretchen Whitmer, a Democrat, extended her stay-at-home order through May 15, while allowing some outdoor activities to resume, including golfing and boating. Her new order said that businesses including garden stores and bicycle repair shops can resume work.

“As hard as this moment is for us right now,” Whitmer said, a second wave of infection “is likely and would be even more devastating than the moment we are in” if Michigan reopens too soon.

The U.S. Navy also reported a new coronavirus outbreak on a warship at sea, saying that at least 18 cases had emerged on the USS Kidd, deployed this month in the Pacific Ocean.

Beyond the United States, Germany’s public health agency said the confirmed cases of coronavirus there need to fall by several hundred a day before the government can consider lowering restrictions.

Germans should not expect the current relaxations in restrictions to lead to a “landslide” of other openings, officials at the Robert Koch Institute warned. On Friday, Germany, which has been more successful in stemming the virus than many other nations, recorded more than 2,000 new cases for a total of more than 153,000. Deaths increased to 5,575.

Spain, one of the hardest-hit countries, for the first time in weeks reported more patients recovered from the virus than new infections. After 40 days of strict lockdown, authorities there reported 2,796 new confirmed infections and 367 deaths, as well as 3,105 recoveries. Spain’s 22,500 deaths are the third-most of any nation, trailing only Italy and the United States.

The rate of confirmed cases continued to rise in Russia, with 5,849 new infections reported Friday and 60 new deaths, bringing the official tally to 615 fatalities and 68,622 confirmed cases. Physicians inside Russia warned that the situation is far worse than the official reports.

A British government online system to sign up for COVID-19 testing was overwhelmed and closed just hours after opening up for testing for millions of essential workers. Citing significant demand, a message posted on the site advised signing up “later.”

The Washington Post’s Tony Romm, John Wagner, Laurie McGinley, Eva Dou, Lisa Rein, Jacob Bogage, Miriam Berger, Erica Werner, Dan Lamothe, Mark Berman, Seung Min Kim, Josh Dawsey, Jeff Stein and Nick Miroff contributed to this report.