The Uriminzokkiri, the North Korean propaganda Web site, linked the plan to what it called South Korean President Lee Myung-bak's "toadyism" to the United States and Japan, Yonhap News Agency reported.
The Web site accused Lee of trying to collude with Japan in military matters.
The North Korean response came days after Japan's Kyodo News reported Tokyo plans to deploy Aegis destroyers near the Yellow Sea to improve its ability to detect a North Korean rocket launch.
Yonhap noted rockets launched from North Korea have soared over Japanese territory.
South Korea's Munhwa Ilbo newspaper, citing an unidentified senior South Korean presidential official, reported Monday South Korea doesn't oppose Japan's plan to deploy the destroyers.
Yonhap said South Korea is seeking to complete a military cooperation agreement with Japan. Japan has no formal ties with South Korea but normalized relations with the country in 1965, Yonhap said.
Seoul and Tokyo want to share intelligence on North Korean missile and nuclear threats, the South Korean news agency said.