US President Donald Trump has signed a massive US$900 billion pandemic relief package that will deliver long-sought cash to businesses and individuals.
The bill includes US$1.4 trillion to fund government agencies through September and contains other end-of-session priorities such as money for cash-starved transit systems and an increase in food stamp benefits.
Democrats are promising more aid to come once President-elect Joe Biden takes office, but Republicans are signaling a wait-and-see approach.
Trump blindsided members of both parties and upended months of negotiations when he demanded last week that the package — already passed the House and Senate by large margins and believed to have Trump's support — be revised to include larger relief payments and scaled-back spending.
The federal government was poised to run out of money and shut down on Tuesday if Trump had continued his opposition to the bill.
Aside from unemployment benefits and relief payments to families, money for vaccine distribution, businesses, cash-starved public transit systems and more was on the line. Protections against evictions also hang in the balance.
"What the President is doing right now is unbelievably cruel," said Senator Bernie Sanders.
"So many people are hurting... It is really insane and this president has got to finally... do the right thing for the American people and stop worrying about his ego."
Republican Senator Pat Toomey of Pennsylvania said he understood that Trump "wants to be remembered for advocating for big cheques, but the danger is he'll be remembered for chaos and misery and erratic behaviour if he allows this to expire."
Republican Representative Adam Kinzinger said too much was at stake for Trump to "play this old switcheroo game".
"I don't get the point," he said. "I don't understand what's being done, why, unless it's just to create chaos and show power and be upset because you lost the election."
Trump, who spent much of Sunday at his West Palm Beach golf course, gave no indication that he planned to sign the bill aside from a vague message posted on social media.
Indeed, the President's dissatisfaction with the legislation only seemed to have grown in recent days as he criticised it both privately to club members and publicly on Twitter.
Days ago, Democrats said they would call House lawmakers back to Washington for a vote Monday on Trump's proposal to send out US$2000 relief checks, instead of the US$600 approved by Congress. But the idea faced staunch opposition in the Republican-controlled Senate.