Donald Trump is floating the notion of ending a national shutdown as soon as next week, with his treasury secretary suggesting the administration thinks the coronavirus outbreak could be over in as few as 10 weeks.

The president used a late-night tweet then a handful of re-tweets Monday morning to signal he is worried enough about the fate of the US economy – which economic experts, as well as Republican and Democratic lawmakers say could careen into a recession – that he could declare the shutdown over when a 15-day period the White House set to separate Americans to slow COVID-19's spread ends on 30 March.

"WE CANNOT LET THE CURE BE WORSE THAN THE PROBLEM ITSELF. AT THE END OF THE 15 DAY PERIOD, WE WILL MAKE A DECISION AS TO WHICH WAY WE WANT TO GO!" the president tweeted just after midnight.

Later on Monday, Treasury Secretary Steven Mnuchin, Mr Trump's point man for trying to negotiate a $1.6trn economic stimulus package with lawmakers, put the administration's first finite timeline on when the outbreak might be considered quelled inside the United States.

"I'm very hopeful that we're going to kill this virus in that time period, if not shorter. So I spoke to the president last night. I know he is very pleased with the medical professionals and ... the movement, some of these new drugs that have been approved," Mr Mnuchin told Fox Business Network.

He was referring to drugs to treat Malaria that Mr Trump is remarkably pushing to also treat coronavirus even as his top public health officials stress any final verdict on their effectiveness will come after a just-started clinical trial.

Mr Trump's treasury secretary said the still-under-discussion stimulus plan, if passed by both chambers and signed into law, is designed to brace the economy for an outbreak lasting 10 weeks to 12 weeks longer.

That means the White House expects the virus's effects to stretch into late May or early June.

"But I hope that we don't need to last that long," Mr Mnuchin said. "And for whatever reason this turns out that it's going to last longer, we'll go back to Congress."

Those remarks came as Mr Trump was retweeting some of his supporters, who want the shutdown to end, warning anything longer than 15 days would crater the economy.

"Flatten the curve NOT the Economy," wrote Twitter user @Fedupmil in a post shared with the president's 74.8m followers. "15 days. Then we isolate the high risk groups and the rest of us get back to work before it's all over for everyone!! #Landslide2020".

He also shared this post from Twitter account @steph93065: "Correct. 15 days, then we keep the high risk groups protected as necessary and the rest of us go back to work."

Meantime, Mr Mnuchin called reports the president has considered a national lockdown to try and stifle the virus's spread "fake news."