The Imperial Household Agency complained Sunday it was "highly inappropriate" for news media to report Princess Nori's engagement before it was officially announced.

Shingo Haketa, vice grand steward of the Imperial Household, told a news conference that the 35-year-old and her fiance-to-be, Yoshiki Kuroda, 39, "feel that they do not wish to announce their private engagement yet," as less than a month has passed since deadly quakes hit Niigata Prefecture.

"It is highly inappropriate and most regrettable that a news item concerning an auspicious event of the Imperial family was published in this way without waiting for the Imperial Household Agency's announcement," Haketa said.

He was apparently referring to a report by the Asahi Shimbun, which ran a scoop on the engagement Sunday morning.

The agency said it will not hold any news conferences on the matter until a formal announcement is made. It also urged the media to "behave with good sense," saying, "We are deeply concerned that the publication of the news item may cause great commotion and bring about much trouble for people around the princess's intended fiance."