A trader wears a mask as he works on the floor of the New York Stock Exchange (NYSE) as the building prepares to close indefinitely due to the coronavirus outbreak in New York, US, March 20, 2020. (Photo: Agencies)

The Trump administration on Thursday looked set to join local officials in advising Americans to wear masks when venturing out during the still-exploding coronavirus pandemic, as the US death toll rose by 1,000 in a single day for the first time.

Speaking at a White House briefing, Deborah Birx, a member of President Donald Trump's coronavirus task force, said the US Centers for Disease Control and Prevention (CDC) would in the coming days add a recommendation on masks to guidelines on protective measures.

But Birx said Americans, almost all of whom have been told to stay at home except for essential outings, should not develop a "false sense of security" that they are fully protected from the respiratory illness by covering their faces. Trump, answering questions from reporters at the briefing, said only "if people want to wear them, they can."

As of Thursday evening the US death toll from COVID-19, the respiratory illness caused by the coronavirus, stood at 5,887, with more than 243,000 cases across all 50 states.

Global cases surpassed 1 million on Thursday with more than 52,000 deaths, according to a Reuters tally based on country-by-country data.

White House medical experts have forecast that between 100,000 to 240,000 Americans could be killed, even if the sweeping lock-down orders are followed.

The Trump administration, CDC and public health officials have all wavered on the issue of face masks since the pandemic broke out, initially telling healthy people such measures were unnecessary or even counter-productive.