SEOUL-- A Cheong Wa Dae official said Thursday it would be "very unusual" if Japan's absence from a joint press conference with South Korea and the United States in Washington was due to an ongoing row over Seoul's easternmost islets of Dokdo.

The comment comes after Japanese Vice Foreign Minister Takeo Mori boycotted the joint event following talks with his South Korean and U.S. counterparts in Washington on Wednesday (U.S. time).

The Japanese government said attending the press conference was "inappropriate" in light of its position on Dokdo, apparently referring to the South Korean police chief's visit to the islets on Tuesday.

Tokyo has repeatedly laid claim to Dokdo even though Seoul regained sovereignty over all of its territory following its 1945 liberation from Japanese colonial rule.

"If it is true that they were absent for that reason, it would be very unusual," the official told reporters on condition of anonymity.

"We emphasize once again that Dokdo is our territory historically, geographically and under international law," the official said.

Source: Yonhap News Agency