As US leaders from Congress and the White House toil in high-stakes negotiations on a mammoth $US1 ($A1.7) trillion-plus economic rescue package, President Donald Trump unleashed fury on those questioning his handling of the coronavirus outbreak. It was an extraordinary moment in Washington: Congress undertaking the most ambitious federal effort yet to shore up households and the US economy and an angry president lashing out at all comers. All while the global pandemic and its nationwide shutdown grip an anxious, isolated population bracing for a healthcare crisis and looming recession. When one reporter asked Trump what he would tell a worried nation, the president snapped, "I say that you're a terrible reporter." Despite the enormous pressure on Washington to swiftly act, the challenges are apparent. On Capitol Hill, lawmakers and administration officials laboured late into the evening over eye-popping sums and striking federal interventions, surpassing even the 2008-09 bank bailout and stimulus. "Everybody is working very hard," Treasury Secretary Steven Mnuchin said, exiting one closed-door session and heading into another. But hopes for a tentative deal by the close of Friday faded as the night dragged on. "Our nation needs a major next step, and we need it fast," Senate Majority Leader Mitch McConnell said earlier in the day to an empty chamber, the iconic US Capitol closed to visitors. Preliminary Senate votes are set for Sunday. McConnell said the goal is passage by Monday. At one point, Senate Democratic Leader Chuck Schumer told reporters, "We're making good progress." But Schumer said trying to wrap up "tonight is hard." Mnuchin launched negotiations with McConnell, Schumer and senators from both parties using McConnell's GOP offer as a starting point. But Mnuchin also conferred privately Friday with Schumer and House Speaker Nancy Pelosi as the two leaders pressed for Democratic priorities. Pelosi late Friday called the GOP plan a "non-starter." The GOP plan aims to pump billions into $US1,200 ($A2,071) direct cheques to Americans and billions to small businesses to pay idled workers during the global pandemic. But Democrats say McConnell's plan is insufficient, arguing for greater income support for workers and a "Marshall Plan" for the US healthcare industry, which is preparing for an onslaught of newly sick patients. At the White House, Trump welcomed the stimulus plan, believing it is needed to stabilise the economy. But Trump spent much of Friday's daily briefing in a fury, an angry president lashing out at reporters' questions. At times, he seemed to refuse to want to hear the reality of an increasingly dire situation. It was when one reporter noted the hard facts in the US - that more than 200 are dead, more than 14,000 infected and millions scared - that he snapped back. Trump also sowed further confusion about whether he is using the powers of the Defense Production Act to force American businesses to manufacture needed medical supplies. The administration also announced a further closing of the nation's border, as the US and Mexico agreed to limit crossings to all but essential travel and trade, while the US moved to restrict entry to anyone without documentation. Later Friday, the White House said a member of Vice President Mike Pence's staff had tested positive for the new coronavirus. Pence spokeswoman Katie Miller said the staff member, who is not being identified, did not have "close contact" either the vice president or Trump. Trump has already signed into law a $US100 billion-plus bill to boost testing for the coronavirus and guarantee paid sick leave for millions of workers hit by it. Earlier, Trump signed an initial $US8.3 billion package from Congress. For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The vast majority of people recover from the new virus. According to the World Health Organisation, people with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover. Australian Associated Press