The Imperial Household Agency is making final arrangements for Crown Prince Naruhito and Crown Princess Masako to attend the coronation of the new Dutch king later this month, agency sources said Wednesday.

It would be the first official overseas trip in 11 years for the Crown Princess, who continues to receive treatment for a stress-induced illness. Her last such engagement was in 2002, when she traveled to New Zealand and Australia.

The agency is in the stages of formally replying to the Netherlands that the couple will be able to attend the coronation of Prince Willem-Alexander, which is slated for April 30, the sources said.