US President Donald Trump speaks during the daily briefing on the novel coronavirus, which causes COVID-19, in the Brady Briefing Room at the White House on April 13, 2020, in Washington, DC.

President Donald Trump said growth in new coronavirus infections stabilized and new hospitalizations in hot spots like New York slowed over the weekend, providing "clear evidence that our aggressive strategy to combat the virus is working."

"Over the weekend, the number of daily new infections remained flat, nationwide flat," Trump said at a White House press conference with the coronavirus task force on Monday. "Hospitalizations are slowing in hot spots like New York, New Jersey, Michigan and Louisiana. This is clear evidence that our aggressive strategy to combat the virus is working and that Americans are following the guidelines."

Treasury Secretary Steve Mnuchin said Trump will decide later this week whether to reopen the country for business by May 1.

Mnuchin said the administration is seeking advice from more than 100 U.S. business leaders on how and when to start easing government restrictions.

"We want to be very, very safe. At the same time, we've got to get our country open," Trump said.

New coronavirus infections appear to have slowed in some of the hardest-hit states, state officials say. New York Gov. Andrew Cuomo said earlier Monday the death toll for Sunday was 671, down from 758 on Saturday. He added that the state, which is the epicenter of the outbreak in the country, is "controlling the spread" of the coronavirus, and it appears that "the worst is over ... if we continue to be smart going forward."

New Jersey confirmed 3,219 new cases on Sunday, a 4% jump from the previous day and the lowest percentage increase in new infections since the Covid-19 outbreak began, Gov. Phil Murphy said Monday.

The virus has now infected more than 577,307 people in the U.S. and killed at least 23,232 people, according to data compiled by Johns Hopkins University.

"You looked at the charts and the models from early predictions where 100,000 and 120,000 people it looked like, if they did well, they were going to unfortunately perish and we are going to be hopefully way, way below that number," Trump said. "That will be a sign of people doing things right, but it's still just a horrible thing."

Coronavirus Response Coordinator Dr. Deborah Birx said the outbreak in some metropolitan areas outside of the New York and New Jersey metropolitan area, where there are roughly 250,000 cases, is starting to plateau. She cited a slowdown of new cases in Detroit, Philadelphia and Louisiana.

"Not only are the curves in some of those major metro areas flattening, but they are starting to decrease," she said. "And that's what we're really excited about."

Trump said the U.S. is racing to get more ventilators built, signing new contracts with General Electric, Hillrom, Medtronic, ResMed and Vyaire to produce ventilators on top of previously signed deals with General Motors, Philips, Hamilton and Zoll. The contracts fall under purview of the Defense Production Act, a statute that gives the White House authority to compel companies to manufacture much-needed goods, he said.

"We're adding 6,190 ventilators to the strategic national stockpile," he said. "This will be added by May 8. Another 29,000 by the end of May and more than 120,000 total we will have by the end of the year."

The U.S. has ramped up its testing in recent weeks, processing 3 million tests so far, up from roughly 300,000 tests about three weeks ago, Birx said. She said the Trump administration is continuing to increase the country's capacity to test for Covid-19.

"As these epidemics decrease, you can use more testing for surveillance," Birx said.

Trump said "per capita testing in New York is higher than anywhere else in the world."

However, not everyone in the U.S. who needs to be tested is able to receive one and many states are forced to ration testing due to a lack of supplies, local and state officials have said. New York City Mayor Bill de Blasio said earlier Monday that the city still has to prioritize who receives testing because supplies, from kits to swabs, remain scarce.