Chinese President Xi Jinping (R) walks next to Sultan of Brunei Haji Hassanal Bolkiah (L) before a signing ceremony at the Great Hall of the People in Beijing, China, 06 February 2025. EPA-EFE/ANDRES MARTINEZ CASARES / POOL 
Prime Minister Anwar Ibrahim, the current chair of the Association of Southeast Asian Nations, was responding to a question during a press conference on whether the 78-year-old sultan had been admitted to the National Heart Institute in Kuala Lumpur.
"He's a little bit tired and resting," Anwar said, confirming that the sultan had been admitted to the institute. He did not elaborate.
The sultan has ruled the oil-rich nation of Brunei, on the island of Borneo, since 1967. He was once the world's richest man and remains hugely popular, despite holding a firm grip on power in the country of nearly half a million people.
Under his rule, Brunei gained full independence from Britain and oversaw a rise in living standards to among the highest in Asia.
(Reporting by Danial Azhar; Writing by Martin Petty;Editing by Ros Russell)