US President Donald Trump, still being treated for Covid-19, abruptly ended talks with Democrats on an economic aid package on Tuesday, drawing criticism from presidential rival Joe Biden that he was abandoning Americans in the midst of a pandemic.

Trump is quarantining in the White House with a case of Covid, and the latest batch of opinion polls shows him significantly behind former Vice President Biden with the election four weeks away.

Trump’s tweet breaking off talks for a new round of stimulus spooked Wall Street, sending stocks down as much as 2 per cent from their session highs and tarnishing one of the metrics that the Republican president has touted as a sign of his success.

Trump tweeted that House Speaker Nancy Pelosi was “not negotiating in good faith” and said he’s asked Senate Majority Leader Mitch McConnell to direct all his focus before the election into confirming his US Supreme Court nominee, Amy Coney Barrett.

“I have instructed my representatives to stop negotiating until after the election when, immediately after I win, we will pass a major Stimulus Bill that focuses on hardworking Americans and Small Business,” Trump tweeted.

Hours later, Trump appeared to edge back a bit from his call to end negotiations. He took to Twitter again and called on Congress to send him a “Stand Alone Bill for Stimulus Checks ($1,200)” — a reference to a pre-election batch of direct payments to most Americans that had been a central piece of negotiations between Pelosi and the White House. Pelosi has generally rejected taking a piecemeal approach to Covid relief.

“I am ready to sign right now. Are you listening Nancy?” Trump said in a flurry of tweets on Tuesday evening. He also called on Congress to immediately approve $25 billion for airlines and $135 billion the Paycheck Protection Program to help small businesses.

Along with Democrat Biden, the former vice president who Trump will face in the Nov 3 US election, congressional Democrats and some Republicans blasted the president, saying more was needed to help the millions who have lost their jobs in a crisis in which the United States leads the world in deaths and infections.

“The president turned his back on you,” Biden said in a Twitter post.

Trump, 74, returned to the White House on Monday after three nights at a hospital to be treated for the novel coronavirus. His doctor said on Tuesday that Trump reported no Covid-19 symptoms and was doing “extremely well”.

But the disease continues to spread among Trump’s top aides, with White House senior policy adviser Stephen Miller saying he tested positive on Tuesday.

The top US military leaders are also isolating after the Coast Guard’s No 2 tested positive for the disease, Pentagon officials said.

Officials said Trump was working from makeshift office space in the residence rather than the Oval Office, with few senior staff given face-to-face access exactly four weeks before the U.S. election in which he is seeking a second term.

‘Forget about him’

Democratic House of Representatives Speaker Nancy Pelosi dismissed Trump’s comment, saying he would lose the election and Congress would pass stimulus during the “lame-duck” session when a president awaits replacement by his successor.

“Forget about him. Four weeks, six, seven hours from now, lame duck,” she said in an online conversation on Tuesday evening with journalist Jonathan Capehart, using a term that also denotes the dwindling powers of a departing president.

But Senate Majority Leader Mitch McConnell, a Republican, said he agreed with Trump, telling reporters that “his view was that they were not going to produce a result and we need to concentrate on what’s achievable".

McConnell plans to focus on pushing through the confirmation of Trump’s third Supreme Court nominee, Amy Coney Barrett, which would cement a 6-3 conservative majority.