The U.S. Senate on Thursday confirmed 48 of President Donald Trump's nominees in a single vote after Republicans changed the rules to allow batch approvals.

The Republican-controlled Senate approved a slew of Trump picks by a 51-47 party-line vote, including several ambassadorial appointments.

Former Fox News host Kimberly Guilfoyle was confirmed as U.S. ambassador to Greece, while Callista Gingrich, wife of former House Speaker Newt Gingrich, was appointed U.S. ambassador to both Switzerland and Liechtenstein. Brandon Williams was confirmed as under secretary for nuclear security at the Department of Energy.

Earlier, Senate Republicans overturned existing rules with a simple majority, bypassing the 60-vote threshold to confirm nominees in batches.

Senate Majority Leader John Thune has repeatedly accused Democrats of unprecedented obstruction and delaying the confirmation of Trump nominees, saying that it had rendered the Senate dysfunctional.

Senate Minority Leader Chuck Schumer, meanwhile, said Trump has been choosing "historically bad nominees."

"I believe it won't take very long for Republicans to wish they had not pushed the chamber further down this awful road," said the top Democrat in the upper chamber.