Trump has tapped Musk to run an unofficial government department that will seek to slash public spending. Reports have surfaced about Trump allies being unhappy with Musk’s presence at Trump’s Mar-a-Lago base, attendance at transition meetings, and what appears to be his growing influence on the returning president of the United States.

It's "nice for both of them to have fun," Elon Musk's mother Maye said of the bromance between the world's richest person and the president-elect.

The pair have been inseparable since the election, with Mr Musk accompanying Mr Trump to Washington to meet Republicans in Congress and Mr Trump heading to Texas with Mr Musk to watch a test flight of a rocket built by SpaceX,