US President Donald Trump has hit out at former close ally Elon Musk over the multi-billionaire's plan to launch a new political party. "I am saddened to watch Elon Musk go completely 'off the rails,' essentially becoming a train wreck over the past five weeks," Trump posted on his Truth Social platform on Sunday.

When it comes to bankrupting our country with waste & graft, we live in a one-party system, not a democracy,” Musk said.

"The America Party is formed to give you back your freedom," Musk said, days after Trump debated deporting him.