'We treaded water' -Sen. Romney on late virus testing in U.S.

"By March 6th, the U.S. had completed just 2,000 tests, whereas South Korea had conducted more than 140,000 tests. So partially as a result of that, they have 256 deaths, and we have almost 80,000 deaths." Romney said.

Some experts say testing for the virus in most parts of the country continues to fall short of what would be needed to safely reopen.

Senate Democrats, including Patty Murray, her party's senior member on the Senate health committee, called on Trump to allocate $25 billion in funding to ramp up testing.