WASHINGTON U.S. President Joe Biden on Saturday rebuked what he called "extreme Republicans", saying the party's lawmakers needed to take immediate steps to prevent a government shutdown ahead of a Sept. 30 deadline.

The deal reached between congressional Republican leadership and his administration in May would have funded essential domestic and national security priorities and still cut the budget deficit by $1 trillion over the next 10 years, Biden said at a congressional awards dinner on Saturday.

"Now a small group of extreme Republicans don't want to live up to the deal," he said.

A shutdown would harm food safety, cancer research and children's programs, Biden said, adding that ensuring that the government is funded is one of the core functions of congress.

"[I]t’s time for Republicans to start doing the job America elected them to do. Let's get this done," he said.

Biden also cast his 2024 campaign against likely Republican challenger former President Donald Trump as a battle against political extremism.

"I wish I could say our threat to democracy ended with our victory in 2020 but it didn't," Biden said. "Our democracy is still at stake, don't kid yourself."

(Reporting by Trevor Hunnicut and Joel Schectman; Editing by William Mallard and Jamie Freed)