WASHINGTON, Oct 4 (AFP) - President Joe Biden admitted Wednesday he was concerned that US political turmoil could disrupt wartime aid for Ukraine, but said he would soon give a major speech to convince doubters on backing Kyiv.

"It does worry me," Biden said when asked whether the ousting of Republican House speaker Kevin McCarthy by hardliners in his own party could derail more funds for Ukraine's war effort.

"But I know there are a majority of members of the House and Senate of both parties who have said that they support funding Ukraine," he told reporters at the White House.

A last-gasp deal to avoid a US government shutdown at the weekend contained no fresh funding for Ukraine, and hopes for a quick solution have been further complicated by McCarthy's exit on Tuesday.

Biden's comment reflected a change of tone, as the White House had previously said that he had told allies in a call on Tuesday that he was "confident" of getting fresh aid passed.

The US president said he would now make the case for the importance of helping Ukraine as it battles the full-scale invasion launched by Russia in February 2022.

The United States is by far the biggest supporter of Kyiv, committing more than $43 billion in military assistance to Kyiv so far, while Congress has approved a total of $113 billion in aid including humanitarian help.

"I'm going to be announcing very shortly a major speech I'm going to make on this issue, and why it's critically important for the United States and our allies that we keep our commitment," Biden said.

The president added that the speech would "make the argument that it's overwhelmingly in the interests of the United States of America that Ukraine succeed."

Biden declined to say when he would make the speech, and the White House said it had no further details.

The US has warned that a gap in funding could be disastrous for Ukraine as it seeks to push forward its slow-moving offensive against Russia before winter sets in.

National Security Council spokesman John Kirby warned on Tuesday that existing founds will only last "a couple of months."

Photo from AFP