The Republican leader of the US House of Representatives on Wednesday announced a weekend vote on massive new military aid including some $61 billion in long-delayed support for Ukraine, as well as billions for Israel and Taiwan.

The move could finally get much-needed help to outgunned Ukrainian forces as they battle Russian invaders.

But it also sets up a showdown with House Speaker Mike Johnson's own far-right wing, which for months has been steered by Donald Trump into blocking aid to Kyiv.

"We expect the vote on final passage on these bills to be on Saturday evening," Johnson announced.

Along with the $61 billion for Ukraine, the bills would allocate more than $26 billion for Israel as it wages war against Hamas militants in the Gaza Strip and squares up against regional foe Iran and its proxies.

That includes a key $9.2 billion in humanitarian aid for civilian-packed Gaza, which had been a key requirement for Democrats.

The package also provides $8 billion for self-ruled Taiwan, which China sees as part of its territory and has vowed to retake -- by force if necessary.

For months Johnson has faced huge pressure from the White House and much of Congress to allow the lower house to vote on aid to Ukraine and Israel that was already approved in the Senate.

Johnson had refused to allow a House vote on that $95 billion package, as Republicans wrangled over President Joe Biden's immigration policies.

Instead he is pushing this separate package -- which the White House has appeared to give the cautious nod to, and the Pentagon has urged be passed "as quickly as possible," warning it has already seen a "shift" in Ukraine's ability to hold off Russian forces.

It remains unclear if Johnson's aid bills would pass the House or the Democrat-controlled Senate.

The speaker's majority is razor-thin, and he is facing a potential Republican revolt over his complex plan, with right-winger Matt Gaetz denouncing it as "abject surrender" on CNN.

Conservatives have complained over the billions in aid already spent since the fighting began in February 2022.

They also insist the immigration crisis at the US southern border must be tackled first, despite largely rejecting the February package which included some of the tightest border restrictions in years.

Without the near-total backing of his party, Johnson would be left to rely on votes from Democrats to pass the package, with some such as Rosa DeLauro of Connecticut voicing her support.

The bills "mirror the Senate-passed package" and "provide long overdue humanitarian aid," she said, urging their swift passage.

But that would infuriate Johnson's own party's hard-right faction, potentially putting his job in jeopardy.