President-elect Donald Trump and Elon Musk have big ambitions for making the federal government leaner and more efficient by reviewing its budget and operations from top to bottom.

Former Republican presidential candidate Vivek Ramaswamy will co-lead the newly created department that Trump indicated will operate outside the confines of government.

Trump also singled-out Mr Musk in his victory speech, spending several minutes praising his rocket firm, Space X. Mr Musk's association with the president-elect also boosted the share price of his electric car maker Tesla - and, with it, his net worth, which now stands at an estimated $290bn.