The Senate has passed $95bn (£76.2bn) in war aid to Ukraine, Israel and Taiwan after months of delays and rows - with Joe Biden set to sign the legislation later.
The bill passed the Senate on an overwhelming 79-18 vote late on Tuesday after the House had approved the package on Saturday.
Once signed, the president will start the process of sending weapons to Ukraine, which has been struggling to hold its front lines against Russia.
The legislation would also send $26bn (£20bn) in wartime assistance to Israel and humanitarian relief to citizens of Gaza, and $8bn (£6.4bn) to counter Chinese threats in Taiwan and the Indo-Pacific.
US officials said about $1bn (£802,000) worth of the aid could be on its way shortly, with the bulk following in the coming weeks.
In an interview with The Associated Press shortly before the vote, Senate majority leader Chuck Schumer said if Congress had not passed the aid, "America would have paid a price economically, politically, militarily".
"Very few things we have done have risen to this level of historic importance," he said.
On the Senate floor, Mr Schumer said the Senate was sending a message to US allies: "We will stand with you."
Mr Schumer and Senate Republican Leader Mitch McConnell argued there could be dire consequences for the US and many of its allies if Russian President Vladimir Putin's aggression is left unchecked.
The pair worked with House Speaker Mike Johnson, a Republican, to overcome seemingly intractable Republican opposition to the Ukraine aid.
The House approved the package in a series of four votes on Saturday, with the Ukraine portion passing 311-112.
The $61bn (£48.1bn) for Ukraine comes as the war-torn country desperately needs new firepower and as Mr Putin has stepped up his attacks.
Ukrainian soldiers have struggled as Russia has seized the momentum on the battlefield and gained significant territory.
Mr Biden told Ukrainian President Volodymyr Zelenskyy on Monday the US will send badly needed air defence weaponry as soon as the legislation is passed.
"The President has assured me that the package will be approved quickly and that it will be powerful, strengthening our air defence as well as long-range and artillery capabilities," Mr Zelenskyy said in a post on X on Monday.
[Source: Sky News]