King Salman, 88, was diagnosed with the inflammation after undergoing medical tests, and is being treated with antibiotics in Jeddah, SPA reported on Sunday.
His son Mohammed bin Salman, the Crown Prince and de facto leader of Saudi Arabia, scrapped plans to travel to Tokyo due to his father’s condition.
The Japanese Foreign Ministry said it would seek to re-arrange the trip at a later date.
Earlier on Sunday, bin Salman met with US National Security Adviser Jake Sullivan in the eastern city of Dhahran, SPA reported.
During the meeting they discussed regional developments, including the conflict in Gaza, “the need to stop the war” and how to find a “credible track towards the two-state solution,” the news agency reported.
King Salman underwent surgery in 2020 to remove his gallbladder. He has been King of Saudi Arabia since the death of King Abdullah in 2015.
In 2017, he removed Mohammed bin Nayef as crown prince and appointed his son in his place.
