US President Donald Trump abruptly ended his news conference on Monday, held in the White House Rose Garden, following combative exchanges with reporters.
It came as the number of deaths from COVID-19 rose above 80,000 according to researchers, and amid much scrutiny over the United States' testing programme.
Weijia Jiang of CBS News asked Trump why he was putting so much emphasis on the amount of coronavirus tests that have been conducted in the United States.
'Don't ask me, ask China'
“Why does that matter?” Jiang asked. “Why is this a global competition to you if everyday Americans are still losing their lives and we're still seeing more cases every day?”
Trump replied that “they're losing their lives everywhere in the world. And maybe that's a question you should ask China. Don't ask me. Ask China that question.”
He called for another question, and there was no immediate response.
“Sir, why are you saying that to me, specifically?” Jiang asked. Jiang, who has worked for CBS News since 2015, was born in Xiamen, China, and emigrated to the United States with her family at the age of 2.
Trump said he would say that to “anyone who asks a nasty question.”
“It's not a nasty question,” Jiang said. “Why does that matter?”
Trump again asked for another question, then said, “Nah, that's OK” and waved off CNN's Collins when she approached the microphone.
“You pointed to me,” Collins said.
The president said, “I pointed to you and you didn't respond.” Collins said she was giving Jiang the time to finish her questioning.
“Can I ask a question?” Collins said.
With that, Trump called an end to the news conference, held in the White House Rose Garden, and walked away.
Trump says US has 'prevailed' on testing
Donald Trump insisted his administration had “met the moment” and “prevailed” on coronavirus testing.
After two aides tested positive for COVID-19 late last week, anyone entering the West Wing was ordered to wear a mask. The president himself did not when he appeared at the briefing.
Monday's briefing was meant to highlight the availability of testing as the White House seeks to convince Americans the country is safely reopening.
Trump repeated his claim that everyone who wants a test can get one. The pledge, first issued more than two months ago, comes as governors across the country continue to call on the federal government to do more to boost supply to meet the requirements.
“They should all be able to get a test right now," Trump said, even though experts say there is no capacity for testing on that scale. Officials later clarified that “everybody who needs a test can get a test."
On a call with state governors, Vice-President Mike Pence and Dr Deborah Birx, the White House coordinator for the virus response, recommended that every nursing home occupant and staffer be tested for COVID-19 in the next two weeks, with vigilant monitoring going forward, especially of staff.
The White House was moving to daily testing of some staff members to detect the disease, AP reported.
US COVID-19 deaths pass 80,000 - Johns Hopkins
The number of people killed by coronavirus amid the pandemic has risen to 80,684, according to latest data from the Johns Hopkins Coronavirus Resource Center.
As of 1130 CEST on Tuesday morning, it put the total number of confirmed cases in the United States at 1,347,936.