U.S. President Donald Trump said on Thursday that Americans should wear protective face masks if they wish, but insisted that he was not considering making it mandatory for all Americans to cover their faces.

As of Thursday evening, the United States had a total of more than 243,000 declared cases and over 5,900 fatalities, according to a running tally by Johns Hopkins University.

Meanwhile, New York mayor Bill de Blasio urged all of the city's residents to cover their faces when outside and near others to help stop the spread of the coronavirus.

"Let's be clear. This is a face covering. It could be a scarf. It could be something you create yourself at home. It could be a bandana," de Blasio told reporters, as the city recorded almost 50,000 confirmed cases, including 1,562 deaths.

At his daily White House news briefing, Trump said Americans should wear protective face masks if they wish. "If people want to wear them, they can" he said. Scarves work just as well, he said.

"In many cases, scarves are better. It's thicker. Depending on the material, it's thicker," he said.

Dr. Deborah Birx, a member of Trump's coronavirus task force, said the Centers for Disease Control and Prevention (CDC) is working on a recommendation about masks to add to U.S. guidelines on how Americans can best protect themselves.

Vice President Mike Pence added that the CDC would release official guidelines on masks in the coming days.

Citing insider sources, U.S. online media The Daily Beast reported on Thursday that the announcement of new guidelines on wearing face masks was delayed due to concerns that they might directly contradict previous guidelines.

According to two senior administration officials, the White House's coronavirus task force is likely to announce new guidelines that Americans wear masks or other protective facial cloth to prevent the spread of coronavirus, the report said.

But it was delayed partly because the administration fears the new guidelines directly contradict those previously pushed out by the federal government. The change in messaging could raise questions about whether the government made a mistake in its original guidelines, it said.

Some officials also worried that the new rules might worsen the supply problems of personal protective gear, including N95 face masks, sources said.

Speaking to reporters at the White House, Birx stressed that it is important people do not think masks replace social distancing or hand-washing.

"We don't want people to get an artificial sense of protection," she said. "They're an additive."

Birx also said data showed not enough people were following the new social distancing guidelines. The recommendations, first unveiled on March 16, encourage people not to gather in groups larger than 10 and to avoid dining in restaurants or bars.

"When we said that, now over 16 days ago, that was serious," Birx said, noting that the people who were now becoming sick would have gotten the virus after the guidelines first went out.

But the president, standing near the White House podium where Birx was speaking, interceded.

"Deborah, aren't you referring to just a few states, because many of those states are dead flat," Trump said, referring to states where the virus had not taken off dramatically and pushed up the national "curve" of deaths.

Birx responded that it was true that some states were flat but that an outbreak in a new city would spoil that.

'P Act' all the way

White House senior adviser Jared Kushner, a member of the coronavirus task force, said the government will send to the New York public hospital system 200,000 N-95 protective masks to help medical workers get through the next month.

Trump, who had initially played down the threat from the virus, made use of the Korean War-era Defense Production Act to order companies to produce hospital ventilators essential in keeping alive patients hit hard by the COVID-19 respiratory illness caused by the coronavirus.

He said he used the law to get General Motors Co to produce more N-95 masks. He also said he got 3M to do "what they are supposed to do," without elaborating.

Later, the president slammed 3M, a Minnesota-based company, in a tweet: "We hit 3M hard today after seeing what they were doing with their Masks. 'P Act' all the way." 

"Big surprise to many in government as to what they were doing – will have a big price to pay!" Trump said on Twitter.

White House trade adviser Peter Navarro said at the briefing, "We've had some issues making sure that all of the production that 3M does around the world, enough of it is coming back here to the right places."

3M did not immediately respond to a request for comment.

Second test negative

Speaking about the country's capacity to test people, Trump said he underwent a second coronavirus test on Thursday, using a new diagnostic that produced a result in less than 15 minutes, and it determined he has not been infected.

"I think I took it really out of curiosity to see how quickly it worked," said Trump, who also tested negative last month after coming into contact with a Brazilian official who later tested positive for the coronavirus.

A White House official said Trump took the newly released Abbott Laboratories test that offers results in 15 minutes or less.

"We're now conducting over 100,000 coronavirus tests per day, with promising innovations in progress," the president said.

(With input from Reuters, AFP) 

(Cover: U.S. President Donald Trump speaks about coronavirus in the James Brady Press Briefing Room of the White House, April 2, 2020, in Washington. /AP)