President Yoon Suk Yeol making a speech at the U.N. General Assembly in New York, Sept. 20. Yonhap

North Korea on Monday lambasted South Korean President Yoon Suk Yeol for making "hysterical" remarks after he warned against possible military cooperation between Pyongyang and Moscow last week.

Yoon said in a U.N. General Assembly speech that any arms deal between Pyongyang and Moscow would be considered a "direct provocation" against South Korea, amid growing concerns about their military cooperation in the wake of a summit between North Korean leader Kim Jong-un and Russian President Vladimir Putin.

"Puppet traitor Yoon Suk Yeol ... malignantly slandered the relations between the DPRK and Russia," the North's official Korean Central News Agency (KCNA) said in an English-language dispatch, using the acronym for the North's official name, the Democratic People's Republic of Korea.

"It was just the height of irony that the puppet with no elementary political knowledge and common sense of the international relations behaved rudely, voluntarily acting as a servile trumpeter and loudspeaker for the U.S.," it said.

The KCNA said it is natural for neighboring countries to keep close relations with each other and the development of friendship and cooperation among nations is the legitimate right of a sovereign state and the foundation for regional and global peace and stability.

"No one in the world would lend an ear to the hysteric fit of puppet traitor Yoon Suk Yeol who is only wearing disgraceful ill fames of 'political immature,' 'diplomatic idiot' and 'incompetent chief executive,'" it said. (Yonhap)