PHNOM PENH, July 5 -- Cambodian King Norodom Sihamoni and his mother, former Queen Norodom Monineath, left here for Beijing, the capital of China, on Tuesday for a regular medical checkup.

At the Phnom Penh International Airport, the royal family was seen off by Prime Minister Samdech Techo Hun Sen and Chinese Ambassador to Cambodia Bu Jianguo as well as other dignitaries.

In a royal message to the compatriots, Sihamoni, 63, said that his trip to Beijing is to have his health checked up.

"During my absence, Samdech Say Chhum, president of the Senate, will assume the title of the acting head of state of the Kingdom of Cambodia," he said.

The king usually has his health checked up by Chinese doctors twice a year.