US President Joe Biden delivers remarks on democracy, while honoring the legacy of late US Senator John McCain, at the Tempe Center for the Arts in Tempe, Arizona, on September 28, 2023.

President Joe Biden said Sunday that American aid to Ukraine will keep flowing for now as he sought to reassure allies of continued U.S. financial support for the war effort. But time is running out, the president said in a warning to Congress.

"We cannot under any circumstances allow American for Ukraine to be interrupted," Biden said in remarks from the Roosevelt Room after Congress voted late Saturday to avert a government shutdown by passing a short-term funding package that dropped assistance for Ukraine in the fight against Russia.