President Donald Trump is considering measures to reopen the United States economy, even as the highly contagious coronavirus is spreading rapidly and hospitals are bracing for a wave of virus-related deaths.

Trump senior economic adviser Larry Kudlow told Fox News on Monday: "The president is right. The cure can't be worse than the disease. We're going to have to make some difficult trade-offs."

The White House would look at "a number of things," he said.

Trump issued guidelines a week ago that he said aimed to slow the spread of the disease over 15 days, including curbing unnecessary travel. Economic activity has ground to a halt in some states.

Late on Sunday, Trump tweeted: "We cannot let the cure be worse than the problem itself," adding that at the end of the 15-day shutdown period, "we will make a decision as to which way we want to go."

Trump, who had hoped to build his campaign for the November 3 election on a booming US economy, now is looking at the potential of millions of lost jobs. Many of his Republican allies fear the toll on the economy would make it harder for him to win another four-year term.

Cases of coronavirus have grown more than 15 times since last week's guidelines. New York City hospitals are days from a crisis, Mayor Bill de Blasio said on Sunday. "If we don't get more ventilators in the next 10 days, people will die who don't have to die," he said.

Republican Senator Lindsey Graham, a Trump confidant, cautioned against prematurely lifting containment rules because of concerns about the economy.

"My advice would be to follow medical advice to contain the virus," he told reporters on Capitol Hill. "If we can take some pressure off the economy, fine, but my primary focus is to make sure the virus is contained and defeated. And we're just going to have to suffer through the economic consequences."

The Trump administration has been pushing for aggressive monetary policy steps to stem the economic hit of the epidemic, after the president spent several weeks playing down the health risks and rapid spread.

The Federal Reserve on Monday rolled out an extraordinary array of programmes to backstop an economy reeling from sweeping restrictions on people and businesses that scientists say are needed to limit the spread of the coronavirus.

While Trump ponders ways to reopen at least parts of the economy, some advisers are warning the spread of the virus is worsening at the moment.

"This week, it's going to get bad," Surgeon General Dr Jerome Adams told NBC's Today show on Monday.

Americans aren't taking stay-at-home guidelines seriously enough, Adams said.

Treasury Secretary Steve Mnuchin said on Sunday that the lockdown affecting large segments of the American public was likely to last 10 to 12 weeks, or until early June.