Donald Trump announced his administration will propose Congress pass a "substantial" coronavirus economic stimulus package as the number of cases and deaths on US soil continue to climb.

Specifically, the president said at a Monday evening press conference he will ask lawmakers to approve a payroll tax cut and assistance for hourly workers "so that they can be in a position to never miss a paycheck."

The president appeared at a twice-delayed press briefing with only brief remarks, leaving without taking questions and leaving his coronavirus task force behind to field inquiries from reporters.

But before he departed, the president said he would return Tuesday afternoon to announce economic stimulus plans he called "major" and "very dramatic."

The president is banking on a solid economy as the basis of his reelection sales pitch as the virus has killed 26 people in the United States, with 666 confirmed cases.

Those comments were perhaps the first time he has sounded so serious and dire about the disease's threat not so much to Americans but to the country's economy. It was a different message from a morning tweet in which he almost mocked coronavirus by stating seasonal flu annually kills many more Americans than this new virus is projected to this year.

Mr Trump called the US economy "great" but said coronavirus "blindsided the world," before declaring of his administration: "I think we've handled it very, very well."

The White House's coming plan also will proposed loan monies for small businesses, he said.

The president told reporters he would return to the James Brady Briefing Room on Tuesday afternoon following "a lot of important meetings" between his team and members of Congress.

Both chambers are slated to be out of session next week, meaning they would have to quickly agree to a stimulus package and speed it to his desk before they adjourn later this week.

Trump left the room ignoring shouted questions about whether he has been tested after interacting with multiple lawmakers in recent days who are now self-quarantining following contact with an infected individual, including Congressman Matt Gaetz – who rode on Air Force One on Monday and found out about his exposure on the executive jet. Vice President Mike Pence promised to get reporters an answer on whether the president had been tested, saying he – Pence – has not.

The vice president, who Mr Trump placed in charge of the federal response, said the risk of contracting the virus to Americans and to becoming seriously ill both remain "low."

His comment came amid recession talk after US and global markets dipped sharply, with the Dow Jones Industrial Average off more than 2,000 points.

But the situation is expected to get worse, he said, acknowledging: "There will be additional cases" as CDC Director Robert Redfield announced there are cases in 35 states.