Some federal agencies, including the State and Defense Departments, told their employees not to respond to an email asking for a list of tasks they completed.

"You know, we got a partial response. We are going to send another email," Musk said while attending President Donald Trump's first cabinet meeting.

Musk is "an employee of the White House Office" and "holds a position as a non-career Special Government Employee," the filing said. "Like other senior White House advisors, Mr Musk has no actual or formal authority to make government decisions himself."