US President Joe Biden signed a hard-fought bill into law on Wednesday that provides billions of dollars of new US aid to Ukraine for its war with Russia, notching a rare bipartisan victory for the president as he seeks reelection and ending months of wrangling with Republicans in Congress.

"It gives vital support to America's partners so they can defend themselves from threats to their sovereignty," Biden said.

The bill includes US$61 billion in aid to Ukraine and US$26 billion for Israel, as well as US$1 billion in humanitarian assistance to Gaza.

The impact of the legislation was immediate. Biden said he had approved an initial US$1 billion in weapons supplies for Ukraine and that the flow of these arms would start within hours.

The initial aid package includes vehicles, Stinger air defence munitions, additional ammunition for high-mobility artillery rocket systems, 155mm artillery ammunition, TOW and Javelin anti-tank munitions and other weapons that can immediately be put to use on the battlefield.

Biden, a Democrat who is expected to face Republican former President Donald Trump in the November election, had pressed lawmakers for six months to approve more funding for Ukraine. Trump objected to the Ukraine aid, and some Republicans in Congress refused to back it, questioning whether Ukraine could ever prevail.

Biden thanked House of Representatives Speaker Mike Johnson, the top Republican in Washington, for breaking the deadlock on the legislation and vowed to return soon to addressing border security, a top issue for Republicans.

“This is a reminder of what America can do when we come together despite our differences," he said.

Biden blamed "MAGA Republicans" loyal to Trump for spending months blocking the aid, referring to Trump's Make America Great Again slogan.

He said passage of the legislation sends a direct message to Russian President Vladimir Putin, whose military has been making gains in Ukraine.

"He's failed again. American stands with our friends. ... We bow to no one, no one, certainly not Vladimir Putin," he said. (Reuters)