By Patricia Zengerle

WASHINGTON (Reuters) -Some U.S. Republican lawmakers said on Wednesday they would resist any funding request from Democratic President Joe Biden that combined military aid for Israel and Ukraine, amid resistance from some Republicans to further assistance for Kyiv.

The White House has been weighing whether to make a request to Congress that would lump funding for Israel with that of Ukraine and Taiwan, an administration official said, to improve the chances of gaining passage of assistance for Ukraine's fight to repel Russian invaders.

Biden and members of Congress from both parties have pledged to do everything possible to support Israel after an unprecedented attack by Hamas militants on Saturday from the Gaza Strip that has killed 1,200 Israelis and prompted retaliation against the Palestinian enclave.

But Congress still must address the need to provide more funding for Ukraine. Biden asked Congress in August to approve $24 billion for Ukraine and related international needs, but the request has not been approved.

A relatively small but vocal group of Republicans has criticized Ukraine assistance for months, accusing Kyiv of failing to sufficiently fight corruption, which Ukrainian and U.S. officials deny.

Some Ukraine backers suggested that Biden should ask Congress for a new spending package combining assistance for Israel, Ukraine and Taiwan as it faces increased pressure from China. The United States has been bolstering Taiwan's defense and China has complained about it.

White House national security spokesman John Kirby told reporters at a news briefing on Wednesday that parameters for the administration's additional funding request to Congress had not been finalized.

Some House of Representatives Republicans, already grappling with a leadership vacuum after the historic removal of Representative Kevin McCarthy as speaker last week, said they would oppose a combined request.

"I don't think there’s been an expressed request from Israel yet, but we want to be prepared to help them," Republican Representative Don Bacon told reporters after administration officials conducted a classified briefing on the situation in Israel for the House on Wednesday.

Bacon said he backed both aid to Israel and Ukraine, but thought they should be considered separately. "I support both but I think it would be a mistake to bundle them together," he said.

(Reporting by Patricia Zengerle; additional reporting by Rick Cowan, Moira Warburton and Steve Holland; editing by Jonathan Oatis and Grant McCool)