The row between Elon Musk, the world's richest man, and U.S. President Donald Trump was triggered by stress on both sides and Elon made a mistake by publicly challenging Trump, Musk's father told Russian media in Moscow.

In an interview with NBC News, the president also said he assumes his relationship with the tech billionaire is over after their recent falling-out.

"They've been under incredible stress for five months, give them a break," Errol Musk said while attending a forum by Putin's ultranationalist ally in Moscow.

Through a panoramic series of actions, President Donald Trump is transforming the federal government into a vast machine for rewarding his allies and punishing those he considers his adversaries.

The blowup between the president of the United States and the world’s richest man has played out on social media in real time, the latest, perhaps ultimate example of how X has become Elon Musk’s personal platform,

Trump warns his former ally against backing any Democratic candidates to challenge the Republicans, as a messy feud between the two escalates.