Elon Musk speaks during an event. File

"Just arrived in amazing Japan," the billionaire said late on Thursday on X, the platform formerly known as Twitter that he bought last year.

In 2014, the CEO of Tesla and SpaceX visited Japan for a ceremony marking his electric car-making company's full-scale entry to the country's market.

During that trip, he briefly met then prime minister Shinzo Abe, who was gunned down last year.

Japanese carmakers are seen by analysts as having fallen behind in the race to develop electric vehicles.

On Friday, Musk also posted videos of what appeared to be an exhibition by prominent Japanese art collective teamLab, which is known for combining projections, sound and carefully designed spaces.

Users on X posted comments asking why Musk was in Japan, with some speculating he had come to see musician Grimes, with whom he has two children, perform at a music festival near Tokyo this weekend.

Since buying Twitter last year for $44 billion, Musk has fired thousands of employees and has erected a paywall on the site, charging users $8 a month to access certain features and get a blue checkmark "verified" account.

Musk visited China in late May, meeting several government officials and declaring he would expand his business in the world's largest market for electric vehicles.

Agence France-Presse