Europe’s oldest monarch, King Harald V of Norway, remains in hospital in Malaysia after falling ill while on holiday.

Malaysian national news agency Bernama said the 87-year-old was undergoing treatment at the Sultanah Maliha Hospital on the country’s northern resort island of Langkawi.

The report cited unnamed sources as saying he was staying at the hospital’s Royal Suite. Norwegian TV 2 said the king’s condition is stable, citing the hospital.

The hospital declined to comment when contacted by The Associated Press. Malaysia’s health ministry told the media to wait for a possible statement.

The royal palace in Oslo said on Tuesday that the king was taken to hospital with an infection but did not give further details. The palace said it may send a statement out later on Wednesday.

Two days before his birthday last week, Norwegian news agency NTB said that the king would be undertaking a private trip abroad together with his wife Queen Sonja, without specifying the destination or dates.

The monarch, who has been seen using crutches in recent years, has been repeatedly ill over the past months, raising concern about the head of state’s health.

In January, the palace said he was on sick leave until February 2 because of a respiratory infection.

In December, he was admitted to a hospital with an infection and was treated with intravenous antibiotics. He also was in hospital last August with a fever.

Harald has repeatedly said he has no plans to abdicate, unlike his second cousin Queen Margrethe II of Denmark, who stunned Danes when she announced her step in a New Year’s speech.

Each time the king was reported ill, his 50-year-old son, Crown Prince Haakon, has taken over his duties in line with the protocol.

The palace in Oslo told NTB said there were no plans to alter a planned trip by Haakon and Crown Princess Mette-Marit on Wednesday and Thursday to southern Norway.

On January 23, Harald said that he stood by the oath he made when ascended the throne in 1991.

“I maintain what I have said all the time. It lasts for life,” he said.