WASHINGTON -- Senior diplomats of the United States and Japan reaffirmed the importance of cooperation with South Korea on Thursday, one day after Japanese Vice Foreign Minister Takeo Mori boycotted a joint press conference over what his US counterpart called an unrelated bilateral issue.

Mori and US Deputy Secretary of State Wendy Sherman also reaffirmed their commitment to the complete denuclearization of the Korean Peninsula, state department spokesman Ned Price said.

"The two also discussed the DPRK and our shared commitment to the complete denuclearization of the Korean peninsula," he said in a released statement. DPRK stands for the Democratic People's Republic of Korea, North Korea's official name.

"They also reaffirmed the importance of US-Japan-Republic of Korea trilateral cooperation, which seeks to tackle the global challenges of the 21st century," he added.

The meeting between Sherman and Mori came one day after they held three-way talks with their South Korean counterpart, Choi Jong-kun.

The trio was originally set to hold a joint press conference following their meeting in Washington, but the event was instead held by the US deputy secretary alone.

Choi later explained the Japanese diplomat refused to take part in the joint press event, taking issue with a recent visit by the head of South Korean police to Dokdo, a set of South Korean islets in the East Sea, to which Tokyo lays territorial claims.

"As has been the case for some time, there are some bilateral differences between Japan and the Republic of Korea that are continuing to be resolved, and one of those differences, which is unrelated to today's meeting, has led to the change in format for today's press availability," Sherman said, referring to South Korea by its official name.

Seoul and Tokyo often find themselves in disputes over history issues. Their relations have been at their lowest ebb since 2019 when Japan took economic steps that were believed to be aimed at retaliating against Seoul court decisions that ordered Japanese firms to pay compensation to Korean workers forced into labor during Japan's 1910-45 colonial rule of Korea. (Yonhap)