President Donald Trump has signed executive orders providing additional financial support to Americans hard hit by the coronavirus pandemic, after his negotiators failed to reach a deal with Congress.

Mr Trump on Saturday said the orders would provide an extra $US400 ($550) per week to the tens of millions thrown out of work during a health crisis that has killed more than 160,000 Americans, less than the $US600 ($830) per week level passed earlier in the year.

Some of the measures were likely to face legal challenges, as the US Constitution gives Congress authority over federal spending.

“This is the money they need, this is the money they want, this gives them an incentive to go back to work,” Mr Trump said of the lower enhanced unemployment payments.

Tens of millions of Americans have lost their jobs in the pandemic. Photo: Getty

Republicans have argued that the higher payments were a disincentive for unemployed Americans to try to return to work, though economists, including Federal Reserve officials, disputed that assertion.

Mr Trump also said he was suspending collection of payroll taxes, which pay for Social Security and other federal programs, an idea that he has repeatedly raised but has been rejected by both Democrats and his fellow Republicans in Congress.

His orders would also stop evictions from rental housing that has federal financial backing and extend zero per cent interest on federally financed student loans, he said.

“Congressional Democrats have stonewalled our efforts to extend this relief,” Mr Trump told reporters at his New Jersey golf club, in a room that featured a crowd of cheering supporters.

House of Representatives Speaker Nancy Pelosi had pushed to extend the enhanced unemployment payments at the previous rate of $US600 per week approved early in the crisis.

Nearly two weeks of talks between White House officials and congressional Democrats ended on Friday with the two sides still about $US2 trillion ($2.8 trillion) apart on next steps to address the heavy human and economic toll the coronavirus pandemic has taken on the United States, where it has killed more than 160,000 people.

Mr Trump initially played down the disease’s threat and has drawn criticism for inconsistent messages on public health steps such as social distancing and masks.

The $US600-per-week increase in unemployment payments that has served as a lifeline to the tens of millions of Americans who lost their jobs in the pandemic expired at the end of July.

Ms Pelosi and Senate Minority Leader Chuck Schumer on Friday offered to reduce a proposed $US3.4 trillion ($4.7 trillion) coronavirus aid package, which the House passed in May but the Senate ignored, by nearly one-third if Republicans would agree to more than double their $US1 trillion ($1.4 trillion) counteroffer.

White House negotiators Treasury Secretary Steven Mnuchin and Chief of Staff Mark Meadows rejected the offer.

Senate Majority Leader Mitch McConnell’s $US1 trillion package unveiled late last month ran into immediate opposition from his party, with as many as 20 of the Senate’s 53 Republicans expected to oppose it.

Democrats have already warned that such executive orders are legally dubious and would likely be challenged in court.

They voiced support for others – Ms Pelosi this week said she would welcome an executive order halting rental evictions.

While Mr Trump had repeatedly floated the idea of executive orders to push relief, Mr Schumer on Friday said the White House team had acknowledged that power was limited.

A court fight could take months, and Mr Trump has managed to sidestep Congress on spending before, declaring a national emergency on the US-Mexico border to shift billions of dollars from the defence budget to pay for a wall he promised during his 2016 election campaign.