U.S. President Donald Trump's adviser Elon Musk said on Monday that starting this week, government workers would be put on administrative leave if they fail to return to the office.

"Those who ignored President Trump’s executive order to return to work have now received over a month’s warning," Musk, the world's richest person who is leading a downsizing effort at the U.S. government, said in a social media post on X.

Federal workers rattled by Trump's chaotic return to power face more uncertainty on Monday, when many of them will be required to justify their jobs to Elon Musk, who has been tasked with slashing the federal budget.

(Reporting by Gnaneshwar Rajan in Bengaluru Editing by Bernadette Baum)