The North Korean leader said the partnership poses a grave threat to his country and vowed to further bolster his nuclear weapons program.

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.

The warning came after Kim accused the US of escalating tensions on the Korean Peninsula through its alliance with South Korea and Japan. View on euronews