US lawmakers worked deep into Tuesday night trying to seal a deal that buttresses the teetering economy by giving roughly $2 trillion to hospitals, businesses and ordinary Americans buckling under the strain of the coronavirus pandemic.

But a full day of intense, protracted negotiating was unable to produce a viable outcome, even as the two sides -- plus the White House -- kept haggling and the US Senate remained in session through midnight.

"At this point, of the few outstanding issues, I don't see any that can't be overcome in the next few hours," top Senate Democrat Chuck Schumer told the chamber after meeting Treasury Secretary Steven Mnuchin.

The US Senate is the focus of negoations on a massive coronavirus economic support package
The US Senate is the focus of negoations on a massive coronavirus economic support package AFP / SAUL LOEB

The historically large measure aims to put cash directly into the hands of Americans hard hit by the crisis, inject billions of dollars into hospitals desperate for medical equipment, provide grants to small businesses and loans for larger corporations, and expand unemployment benefits.

After days of vicious partisan infighting over what to include, in what ultimately may be the largest emergency rescue package lawmakers have ever passed, optimism remained that the package could still pass.

But even several hours after a dramatic rally by Wall Street on anticipation of an agreement on the stimulus package, the deal was not yet done.

Mnuchin, shuttling between the Capitol offices of Schumer and Republican Senate Majority Leader Mitch McConnell as they hammered out the language of the bill, said they were "getting closer" to a final product.

US Speaker of the House Nancy Pelosi has led a group of US lawmakers to Jordan for talks with King Abdullah II
US Speaker of the House Nancy Pelosi has led a group of US lawmakers to Jordan for talks with King Abdullah II AFP / Brendan Smialowski

The Senate failed on multiple occasions in recent days to advance a massive but controversial Republican-led proposal, and pressure has soared to swiftly reach a compromise that provides relief for hundreds of millions of Americans.

President Donald Trump called for an immediate resolution to the stalemate.

"Congress must approve the deal, without all of the nonsense, today," he said on Twitter.

US Senate Majority Leader Mitch McConnell unveiled a measure aimed at injecting huge federal funding into the pockets of struggling Americans and businesses, but Democrats argued it prioritized corporations over workers
US Senate Majority Leader Mitch McConnell unveiled a measure aimed at injecting huge federal funding into the pockets of struggling Americans and businesses, but Democrats argued it prioritized corporations over workers AFP / SAUL LOEB

"The longer it takes, the harder it will be to start up our economy. Our workers will be hurt!"

US stocks soared -- the Dow Jones Industrial Average closed up 11.4 percent -- on the prospects of a stimulus that could send checks to Americans potentially amounting to more than $3,000 for a family-of-four.

Democrats rejected the original Republican package, arguing it put corporations ahead of workers, including health professionals on the front lines of the battle against a pandemic that has infected 55,000 people and killed nearly 800 in the US alone.

As the hours ticked away without a deal, several lawmakers voiced their anxiety.

US Treasury Secretary Steven Mnuchin leaves a meeting in the US Capitol as negotiations on a rescue package for Americans and their economy ravaged by the coronavirus pandemic continue in Congress
US Treasury Secretary Steven Mnuchin leaves a meeting in the US Capitol as negotiations on a rescue package for Americans and their economy ravaged by the coronavirus pandemic continue in Congress AFP / Brendan Smialowski

"Pass the damn bill. Stop negotiating. Enough is enough," a visibly angry Republican Senator Lindsey Graham said on the floor, after accusing Democrats of "nickeling and diming at a time people are dying."

Any relief package that passes the Senate will need to clear the Democratic-led House too before going to the president's desk.

Speaker Nancy Pelosi expressed confidence the Senate deal could be done soon.

"We're in the red zone and hopefully we can get it over the finish line," the powerful California Democrat told CNN.

She suggested the measure might even pass the House by unanimous consent.

But getting 435 lawmakers to swallow a gargantuan rescue package without debate could be an uphill proposition in a sharply divided chamber.

McConnell's opening bid included one-time "recovery rebates" of up to $1,200 for most adults, and hundreds of billions of dollars in loan guarantees to industries hit by the crisis, including airlines, and grants to small businesses.

Democrats fumed that the measure did not mandate that companies keep their employees on payroll.

They also argued it provided insufficient oversight on corporations receiving the infusions, and needed more aid for hospitals in dire need of equipment like protective gear, intensive care beds and ventilators.

Those shortcomings were addressed in the compromise, according to Democratic leaders.

Schumer said it will almost certainly include a guarantee that the federal government will broaden eligibility of unemployment insurance and pay full wages for four months to workers sickened by or laid off due to the pandemic.

Pelosi meanwhile unveiled a more generous, roughly $2.5 trillion counterproposal that included ambitious elements like guaranteed paid and family medical leave, student loan forgiveness and oversight of the $500 billion earmarked for corporations.

"Much of what we have in our bill is reflected in this supposed agreement, what we've seen so far," Pelosi said.