US President Donald Trump holds up swabs as he speaks during a Coronavirus Task Force press briefing at the White House in Washington, DC, on April 19, 2020.

President Donald Trump announced on Sunday that he plans to use the Defense Production Act to increase the nation's swab production by at least 20 million per month for coronavirus tests.

Trump said the administration is close to finalizing a partnership with one manufacturer to produce an additional 10 million swabs per month for coronavirus test kits, which are used to collect specimens from a patient's throat or nose. Trump said he is preparing to use the Defense Production Act on another manufacturer to increase its swab production by over 20 million per month.

Trump did not disclose the names of the manufacturer. A FEMA spokesperson was not immediately available for comment. The president previously enacted the Defense Production Act on companies like General Motors and General Electric to manufacturer additional ventilators, although many had already ramped up production.

"We've had a little difficulty with one so we're calling in, as in the past you know, we're calling in the Defense Production Act and we'll be getting swabs very easily," Trump said. "Swabs are easy. Ventilators are hard."

Trump's announcement comes after some governors cited a lack of swabs and reagents as hampering their ability to conduct more coronavirus tests. Michigan Gov. Gretchen Whitmer told NBC's "Meet the Press" on Sunday that her state could triple the number of tests conducted if the key components were made available.

Whitmer called on the Trump administration to enact the Defense Production Act to ramp up swab and reagent production.

"We don't even have enough swabs believe it or not and we're ramping that up," Virginia Gov. Ralph Northam, a Democrat, told CNN's "State of the Union" Sunday. "But, for the national level to say that we have what we need and really to have no guidance to the state levels is just irresponsible because we're not there yet."

At the White House press briefing Sunday, Trump said that the swabs were previously shipped to the states but some of them "don't know where they are."

"We have them coming by the tens of millions. We have them coming at a level that you'll have so many swabs you won't know what to do with them," Trump said.

Earlier on Sunday, Vice President Mike Pence said the administration has "laid a strong foundation for testing for phase one." He said that there are enough tests for any governor who meets the 14-day criteria of declining case numbers outlined by the White House to move into phase one and begin reopening their state's economy.

Experts have warned, however, against opening the country before widespread testing is available. Some say that as many as 20 to 30 million people per day will need tested before the nation can return to a semblance of economic normality.

There are currently more than 150,000 tests being conducted per day, Pence said, but that number could "double" once laboratories across the country are activated.