SEOUL, South Korea — Top South Korean, U.S. and Japanese military officers urged North Korea to cease all unlawful activities that threaten regional security, as the three nations flew advanced warplanes for a joint exercise in a show of force against the North.
The development came Friday as Russian Foreign Minister Sergei Lavrov was to travel to North Korea amid booming military and other cooperation between the two countries that have raised concerns among their neighbors.
During their regular meeting in Seoul on Friday, the chairmen of the joint chiefs of staff from South Korea, the U.S. and Japan discussed North Korea's deployment of troops to Russia to support its war against Ukraine and Russia's potential transfer of military technology to North Korea in return.
''They urged the DPRK to immediately cease all unlawful activities to destabilize the Korean Peninsula, the Indo-Pacific, and beyond, and pledged to continue working together to respond to the DPRK's threats,'' according to a joint press statement.
DPRK stands for the Democratic People's Republic of Korea, North Korea's formal name.
North Korea and Russia have grown sharply closer in recent years, with North Korea supplying thousands of troops and ammunitions to Russia in return for economic and military assistance. Seoul, Washington and their partners worry Russia might provide North Korea with sensitive technologies that can enhance its nuclear and missile programs as well.
The three joint chiefs of staff chairmen — South Korea's Kim Myung-soo, the United States' Dan Caine and Japan's Yoshida Yoshihide — discussed various ways to deepen their cooperation in order to ensure peace and stability in the region, according to the joint statement.
Also Friday, the three countries staged a trilateral aerial drill in international waters off South Korea's southern Jeju island. The training, which involves nuclear-capable B-52H bombers from the U.S., is meant to improve the deterrence and response capabilities against North Korea's evolving nuclear and missile threats, according to South Korea's Defense Ministry.