The leaders of South Korea, the United States and Japan held a trilateral summit on Sunday in Cambodia and agreed to cooperate in strengthening extended deterrence against North Korea.

President Yoon Suk Yeol held the summit with U.S. President Joe Biden and Japanese Prime Minister Fumio Kishida at a hotel in Phnom Penh on the sidelines of the East Asia summit, after which they adopted a joint statement pledging to further bolster closer trilateral solidarity.

It marks the first time that the leaders of the three nations adopted a comprehensive joint statement.

The three leaders strongly condemned the North's nuclear and missile provocation, while reaffirming their commitment to complete denuclearization of the Korean Peninsula.

The leaders then warned that a nuclear test by the North will be met by a strong and stern response by the international community.

They also agreed to share alarm information about North Korean missiles in real time in order to improve the capabilities of detecting and assessing North Korean missiles. 

In the opening remarks, President Yoon expressed concern about the North's continued provocation, saying that a ballistic missile recently fired by the North landed in South Korean territory, which is the first since the two Koreas were divided.

Calling the launch a grave provocation, Yoon said that the Kim Jong-un regime revealed its inhumane tendency by engaging in provocation when South Korea was in deep sorrow from the Itaewon crowd crush.