Multiple US federal agencies, including some led by prominent Donald Trump loyalists, have pushed back against a move by Elon Musk to force employees to explain what they had achieved at work or risk losing their jobs. 

The resistance signaled a possible rift between key Trump administration figures and Musk, who has spearheaded a campaign to slash the government's millions-strong civilian workforce that has sown confusion across multiple agencies. 

On Saturday, federal employees received an email seen by AFP from the US Office of Personnel Management giving them until 11:59 PM Monday to submit "approx. 5 bullets of what you accomplished last week." 

Not long beforehand, Musk had posted on X that "all federal workers" would receive the email and that "failure to respond will be taken as a resignation."

Federal workers told AFP they had been advised not to reply immediately.

On Sunday, the Defense Department posted a note requesting that staff "pause any response to the OPM email titled 'What did you do last week.'" 

"The Department of Defense is responsible for reviewing the performance of its personnel and it will conduct any review in accordance with its own procedures," it said in a post on X. 

US media reported that Trump administration-appointed officials at the FBI, the State Department and the office of national intelligence also instructed staff not to respond directly. 

The new director the Federal Bureau of Investigation, Kash Patel, sent a message to personnel on Saturday saying, "the FBI, through the office of the director, is in charge of all our review processes," the New York Times wrote. 

Unions also quickly pushed back, with the largest federal employee union, the American Federation of Government Employees (AFGE), vowing to challenge any unlawful terminations.

In a letter to the OPM on Sunday, the AFGE criticized the power given to the "unelected and unhinged" Musk and said the "email was nothing more than an irresponsible and sophomoric attempt to create confusion and bully the hard-working federal employees that serve our country." 

Trump has put Musk — the world's richest person and the President's biggest donor — in charge of the new Department of Government Efficiency (DOGE) advisory body, tasking him with slashing public spending and tackling alleged waste and corruption.

DOGE is a free-ranging entity run by the tech entrepreneur, though its cost-cutting spree has been met with pushback on several fronts and mixed court rulings.