Norway's 85-year-old King Harald, who has  battled poor health, on Tuesday tested positive for Covid-19, the Royal House of Norway said.

"The king has mild symptoms, and will be on sick leave for the next few days," a court statement said.

In the meantime, Crown Prince Haakon would step in to handle the King's royal duties.

Harald, a former Olympic yachtsman who has been on the throne for over 30 years, has refused to abdicate despite several years of ill-health, including an operation for bladder cancer in 2003.

Harald is the last of the Nordic royal heads of state to catch coronavirus.

In early January, Sweden's King Carl XVI Gustaf, 75, and Queen Silvia, 78, both tested positive, followed by Denmark's Queen Margrethe II, 81 in February.