About 75,000 U.S. federal workers accepted the deferred buyout program of President Donald Trump's administration, a spokesperson for the U.S. Office of Personnel Management said late on Wednesday.

The buyout is one of many approaches Trump is taking to slash a civilian workforce of 2.3 million that he has blasted as ineffective and biased against him.

He has also ordered government agencies to prepare for wide-ranging job cuts, and several have already begun to lay off recent hires who lack full job security.

Officials have been told to prepare staff cuts of up to 70% at some agencies, sources say.

Unions had urged their members not to accept the buyout and have warned that Trump cannot be trusted to honor it.

The offer promises to pay employees their regular salaries and benefits until October without requiring them to work, but that may not be ironclad. Current spending laws expire on March 14, and there is no guarantee that salaries would be funded beyond that point.

Trump has deputized billionaire Elon Musk to head the newly created Department of Government Efficiency, which is combing through payment and personnel records in an effort to cut $1 trillion from the federal budget, which totaled $6.75 trillion last year. Civilian worker salaries account for less than 5% of that total.