Saudi Arabian Crown Prince Mohammed bin Salman postponed a planned four-day trip to Japan due to concerns over the king’s health, Japan’s top government spokesman, Yoshimasa Hayashi, said.

The trip, set to start Monday, was to have been the crown prince’s first visit to Japan since 2019. Hayashi said at a regular news briefing in Tokyo the two nations would reschedule the visit, without indicating when.

The kingdom’s de facto ruler was due to meet Prime Minister Fumio Kishida during the trip, according to Japan’s government. MBS, as the Saudi crown prince is known, was also expected to meet Japanese companies and sign an agreement to strengthen supply chains for liquid hydrogen, Japanese media reported.