The top diplomats of the U.S., South Korea and Japan reaffirmed their commitment to North Korea’s complete denuclearization and strengthening trilateral cooperation amid growing concerns over Pyongyang’s military ties with Russia.

U.S. Secretary of State Marco Rubio, South Korean Foreign Minister Cho Tae-yul and Japanese Foreign Minister Takeshi Iwaya pledged to work together against Pyongyang’s military activities in their first trilateral meeting held on the sidelines of the Munich Security Conference on Saturday.

In a joint statementissued after the meeting, the three ministers emphasized their “resolute commitment to the complete denuclearization of North Korea” and expressed concern about Pyongyang’s