North Koreans celebrated the anniversary of the ruling Workers' Party on Monday. It comes after the country confirmed leader Kim Jong Un oversaw training on tactical nuclear arms.

North Koreans took part in a mass dance event celebrating 77 years since the ruling party was founded.
It follows a series of ballistic missile launches over the past few weeks.

On Monday, the Workers' Party newspaper published an article about military exercises that took place. It was the first time that Pyongyang has mentioned the drills of its tactical nuclear arms unit. It says they were meant as a warning after the United States deployed an aircraft carrier during joint exercises in waters east of the Korean Peninsula.

South Korea's President criticized the North's recent moves. Yoon Suk-yeol said, "North Korea is steadily developing and advancing its nuclear weapons, threatening not just South Korea but the whole world. Pyongyang has nothing to gain from nuclear weapons."

Japan's Foreign Minister continued to condemn North Korea. Hayashi Yoshimasa said, "The series of North Korean actions, including repeated launches of ballistic missiles, threaten the peace and security of Japan, the region and the international community, and we believe that this is absolutely unacceptable."

Hayashi said Japan will work with the United States and South Korea on the issue.