Democratic and Republican negotiators agreed early Tuesday morning on the sweeping bill to fund the federal government through the end of its fiscal year on Sept. 30, raising funding from about $1.5 trillion in the last fiscal year.
The Senate voted 70-25 to proceed to debate of the bill, with some Republican senators hoping to offer amendments.
A handful of conservative Senate Republicans on Tuesday said they objected to the bill, but would not try to stop its passage.
"Under no circumstances are we going to go over the shutdown deadline," said Senator Mike Lee, who joined a news conference with four allies to speak out against the measure. Fellow Republican Senator Mike Braun said the group will intensify its budget reform efforts next year, when Republicans take control of the House of Representatives.
"We are not going to win this war with theatrics," Braun added.
The bill includes other measures agreed on by negotiators from both parties, including a ban on the use of TikTok on government-owned devices and clarification of Congress's role in certifying elections, an attempt to avoid a repeat of the violence of Jan. 6, 2021.
Senate and House leaders aim to pass the 4,155-page bill and send it to Democratic President Joe Biden for signing by the end of the week to ensure there are no interruptions to the government's activities.
The Tuesday vote was the first in a series of steps clearing the way for passage by Friday.
Top Senate Republican Mitch McConnell said most of his caucus supports it: "We're moving toward completing the business for the year. And I think in a highly productive way from the point of view of the vast majority of Senate Republicans."
Failure to pass legislation in time could bring a partial government shutdown beginning Saturday, just before Christmas, and possibly lead into a months-long standoff after Republicans take control of the House on Jan. 3, breaking the grip of Biden's Democrats on both chambers of Congress.
Budget experts found fault with the bill's size.
"This budget is too late and too big," said Maya MacGuineas, president of the Committee for a Responsible Federal Budget. She noted that much of the spending increases are to keep pace with inflation, but said, "A lower number would help bring inflation down."
Included in the bill is $44.9 billion in emergency assistance to Ukraine and NATO allies and $40.6 billion to assist communities across the United States recovering from natural disasters and other matters.
The Ukraine funds would be used for military training, equipment, logistics and intelligence support, as well as for replenishing U.S. equipment sent to Kyiv. It also includes funding to prepare for and respond to potential nuclear and radiological incidents in Ukraine. Russian President Vladimir Putin has not ruled out the use of nuclear weapons in the conflict with Ukraine.
Included in the Ukraine package is $13.4 billion in economic aide and $2.4 billion to help resettle Ukrainians in the United States.
The military aid would be on top of the record $858 billion in U.S. defense spending for the year, which is up from last year's $740 billion and also exceeds Biden's request.
On the non-defense side of the ledger, the bill's negotiators have set funding at $800 billion, a $68 billion increase over the previous year. This includes increased healthcare funding for poor children.
Among the most significant add-ons to the spending bill is the bipartisan Electoral Count Act, which overhauls and clarifies Congress' certification process for presidential elections.
Democrats and many Republicans see the measure as crucial to avoiding a repeat of the chaos that occurred almost two years ago when a mob of Donald Trump supporters attacked the Capitol building in an attempt to overturn Biden's victory.
U.S. lawmakers also included a proposal to bar federal employees from using the Chinese short-video app TikTok on government-owned devices. And they backed a proposal to lift a looming deadline imposing a new safety standard for modern cockpit alerts for two new versions of Boeing Co's (BA.N) 737 MAX aircraft.
Measures left out include legislation that would have provided citizenship to "Dreamer" immigrants, who illegally entered the United States as children.
Criminal justice reform advocates came away largely empty-handed, after a compromise measure that would have dramatically lessened the sentencing disparity between crack cocaine and powder cocaine collapsed. And the cannabis industry suffered a defeat after a closely watched measure that would have shored up banking regulations for legal marijuana companies was excluded.