Trump said he expects the U.S. "will be well on our way to recovery" by June 1. He said that helped shape the extension of the guidelines, which he called "a wise and prudent decision".
By now, at least 1 in three Americans are under some form of government order to stay home and slow the spread of the virus.
Trump predicted that the peak of fatalities from the outbreak would come in "about two weeks".
Trump said he is extending the government's "social distancing" guidelines until April 30 to "slow the spread" of the virus.
Speaking on how freezer trucks are being brought to a city hospital in New York, Trump added: "I have been watching them bring in trailer trucks, freezer trucks - they are freezer trucks because they can't handle the bodies there are so many of them". "This is essentially in my community, in Queens, Queens, New York", he continued.
Trump told reporters at a televised White House news conference that he has made the made move after receiving advice from his two top public health advisors, who are also members of the White House Task Force on COVID-19: Dr Deborah Bix and Dr Anthony Fauci.
"I want to see that tests are being implemented on the ground", he added.
The US now has more than 140,000 confirmed cases.
"If you started walling off areas all across the country, it would be totally freakish, counterproductive, anti-American, antisocial", New York Governor Andrew Cuomo said on CNN, also calling it "a declaration of war on states".
"We remain on a trajectory, really, to overwhelm our capacity to deliver health care", Louisiana Gov. John Bel Edwards said on ABC's "This Week".
Dr Fauci said that it was "entirely conceivable" that millions of Americans could eventually be infected.
According to a tally by Johns Hopkins University, there are almost 140,000 confirmed virus cases in the United States and more than 2,400 people have died. During the course of the Rose Garden briefing, reported deaths grew by several dozen and the number of cases by several thousand. More than 20 of the 50 American states have recorded over 1,000 coronavirus cases - the number from where the deadly disease starts skyrocketing. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.
Sending out a dire warning, the White House on Sunday projected America's peak death toll from the coronavirus is likely in two weeks coinciding with Easter weekend and in a worst case scenario, a total of 100,000 to 200,000 Americans could eventually succumb to the virus. Trump repeatedly cited the flu's comparatively much higher cost in lives in playing down the severity of this pandemic.
"We have some healthcare workers, some hospitals. hoarding equipment including ventilators", Mr Trump said at the White House following a meeting with corporate executives, including from US Medical Group.
Earlier on Sunday, Mr Trump accused hospitals in some states of "hoarding" ventilators, face masks and other critical medical supplies. He also encouraged the Food and Drug Administration to streamline approvals for companies seeking to sanitize badly needed respirators so they can be reused.
Trump minimized the gravity of the pandemic for weeks.
Asked whether she believes that attitude cost American lives, Pelosi told CNN: "Yes, I am". "I think that's a little too harsh", he told NBC.