SEOUL (Reuters) -North Korean leader Kim Jong Un criticised trilateral military cooperation among the United States, Japan and South Korea for raising tensions in the region and vowed countermeasures,

North Korean leader Kim Jong Un has vowed to bolster his nuclear weapons program in response to the U.S.’s enhanced security partnership with South Korea and Japan. Last year, the U.S. expanded bilateral military exercises with South Korean and trilateral training with South Korea and Japan.

North Korea has vowed to keep developing nuclear weapons in response to U.S. cooperation with South Korea and Japan.