Lawmakers in the US House of Representatives on Saturday quickly passed legislation to provide more aid to Ukraine and Israel.

The bills, passed in a rare Saturday session, were approved by overwhelming bipartisan votes, though they leave the future of House speaker Mike Johnson in doubt as he seeks to fend off angry far-right detractors.

Ukraine's President Volodymyr Zelensky welcomed the long-delayed aid package, saying the military and economic assistance would "save thousands and thousands of lives."

The bills are the product of months of acrimonious negotiations, pressure from US allies and repeated pleas for assistance from Zelensky.

Spending bills cost the last Republican speaker of the House his job, and funding for Ukraine has been at the heart of the partisan squabbling.

The United States has been the chief military backer of Ukraine in its war against Russia, but Congress has not approved large-scale funding for its ally for nearly a year and a half, mainly because of the cross-aisle bickering.

President Joe Biden and Democratic lawmakers in Congress have been pushing for a major new weapons package for Ukraine for months.

But Republicans, influenced by the party's presidential candidate Donald Trump, have been reluctant to provide funding to Kyiv for the drawn-out conflict.

The financing of the war has become a point of contention ahead of a presidential election in November that is expected to pit Biden against Trump once again.

Johnson, after months of hesitation, finally threw his support behind the US$61 billion package for Ukraine that includes economic assistance and weapons.

"To put it bluntly, I'd rather send bullets to Ukraine than American boys," Johnson said.

Writing on social media after the bill was passed, Ukraine's Zelensky expressed hope that the bill would soon clear the US Senate and be signed into law by Biden. "Thank you, America!" he added.

The bill also allows Biden to confiscate and sell Russian assets and provide the money to Ukraine to finance reconstruction, a move that has been embraced by other G7 nations.

The upper chamber could take the bill up as early as Tuesday, Senate Democratic leader Chuck Schumer said. (AFP)