Norway's Crown Princess Mette-Marit, who suffers from an incurable chronic lung disease and whose condition has recently deteriorated, has been placed on a waiting list for a lung transplant, the royal palace announced Friday.

"The progression of the Crown Princess's lung disease is serious. After a comprehensive medical assessment, she has now been placed on the list of patients who will undergo a lung transplant as soon as it is possible," Are Holm, Professor of Medicine at the University of Oslo and respiratory specialist at Oslo University Hospital, Rikshospitalet, said in a statement from the palace.

Mette-Marit was diagnosed in 2018 with a rare form of pulmonary fibrosis that causes breathing difficulties and which has repeatedly forced her to take sick leave and scale back her official duties.

While awaiting the operation, the Crown Princess will not be able to carry out her official duties, the palace said.

The Crown Prince Haakon will also adjust his agenda and will limit longer journeys both within Norway and abroad before and after the operation.