Elon Musk is leaving Washington after a tenure in government marked by controversy.

He clashed with cabinet secretaries. He took a chain-saw approach to slashing government jobs. He never came close to cutting $1 trillion from the federal budget, like he had promised.

On Friday, President Trump gave him a send-off in the Oval Office that was meant to give him a boost as he turns his focus back to his businesses. Musk, dressed in black and sporting a black eye, stood next to the President during a joint news conference.

Standing by

Trump wanted to send the message that he still supports his billionaire benefactor, who donated about $275 million to help him win the presidency.

The President presented Musk with a golden key and portrayed him as a victim of unfair scrutiny.

"He had to go through the slings and the arrows, which is a shame", Trump said.

Tesla, Musk's carmaker, has faced protests, vandalism and plummeting stock prices as the billionaire deepened his involvement with right-wing politics. The relationship between the two men started out rocky. Musk once suggested Trump shouldn't run for office, and the President brushed him off.

But they formed an alliance that helped Trump return to the presidency. Musk lavished the President with campaign donations and compliments and he, in turn, was given free rein to inject himself into any federal agency.

'Hard' cuts

While Musk seemed to delight in inflicting pain on workers — celebrating layoffs and government cuts by wielding a chain saw — his so-called department of government efficiency never came close to achieving his goal of cutting $1 trillion from the federal budget.

Along the way, he changed his tune on how difficult it was to find the massive cuts in the federal government that he had promised.

Black eye?

Musk appeared to be sporting a black eye. When a reporter asked about it, he explained that he had been "horsing around" with his 5-year-old son, X. "I said, 'Go ahead, punch me in the face'", Musk recalled. "And he did."

Friday's conference was meant to honour Musk, but he was not the centre of attention. Members of the media allowed into the Oval Office directed their questions to the President, and Musk at times looked distracted.

New York Times News Service