By Steve Holland

WASHINGTON President Joe Biden expressed fears on Wednesday that U.S. aid to Ukraine could be hurt by congressional chaos and said he will give a major speech soon to make the case for why it is necessary to help Ukraine repel Russian invaders.

Republican infighting in the House of Representatives has complicated budget negotiations and prompted Biden to go from confidence that an agreement will be made on Ukraine aid to now expressing worries about funding his top foreign policy priority.

Asked if he was concerned that the United States would not be able to deliver the aid that it has promised to Ukraine because of the disarray on Capitol Hill, Biden said: "It does worry me ... but I know there are a majority of members of the House and Senate in both parties who have said that they support funding Ukraine."

Biden asked Congress in July to approve $24 billion more related to Ukraine, which Ukraine supporters - Republicans and Democrats - had hoped could become law as part of a spending bill. The White House said on Tuesday that current funding levels would last about two more months.

Biden sought to assure U.S. allies in a call on Tuesday that U.S. aid would continue unimpeded as Ukrainian forces press on with a counteroffensive to try to reclaim territory lost since Russia's invasion in February 2022.

"The president's message was that the U.S.A. could certainly continue to be relied on in this matter in the future," German Chancellor Olaf Scholz told reporters in Berlin.

Biden did not say when he made deliver his speech on the subject but indicated that it would be soon. The White House declined comment and one official said the speech was not currently on Biden's schedule.

"I'm going to make the argument that it is overwhelmingly in the interests of the United States of America that Ukraine succeed and it's overwhelmingly in our interests," he said.

Biden suggested there was an alternative source for Ukraine funds but did not explain what he meant. The White House declined comment.

A Reuters-Ipsos opinion poll from June said majorities of Americans continue to support the United States providing weapons to Ukraine.

(Reporting By Steve Holland, Jarrett Renshaw and Jeff Mason; additional reporting by Riham Alkousaa in Berlin; Editing by Chris Reese and Grant McCool)