The sister of North Korean leader Kim Jong-un slammed a new South Korea-U.S. agreement aimed at bolstering their nuclear deterrence efforts against North Korean threats, saying the allies' plan will only result in "more serious danger."

In the North's first response to the Washington Declaration adopted during President Yoon Suk Yeol's state visit to the U.S., Kim Yo-jong said that the agreement reflects "the most hostile and aggressive will of action" against the North that will "only result in making peace and security of Northeast Asia and the world be exposed to more serious danger," according to the Korean Central News Agency (KCNA) on Saturday.

Kim, who is known for her influence on inter-Korean affairs in the Kim regime, holding the post of vice department director of the Central Committee of the Workers' Party of Korea, also lambasted U.S. President Joe Biden's warning against North Korea.

During a joint press conference between the leaders, Biden warned Pyongyang that any nuclear attack against the United States or its allies will result in the end of its regime.

"It may be taken as a nonsensical remark from the person in his dotage who is not at all capable of taking the responsibility for security and the future of the U.S., an old man with no future, as it is too much for him to serve out two-year remainder of his office term," Kim said in the English-language dispatch.

The KCNA report came as Yoon's state visit to the U.S. is under way.

Source: Yonhap News Agency