North Korea's foreign ministry on Sunday criticized Japan's moves to revise a set of key security documents as "extremely dangerous" steps away from its long-held defense-oriented policy.

Japan has reportedly been moving to revise its national security strategy and other key defense documents this year as it confronts an increasingly assertive China and a nuclear-ambitious North Korea.

"What is extremely dangerous is that Japan is poised to include in these documents capabilities to attack enemy bases, a sharp increase in defense spending, and the development and purchase of armament equipment for preemptive strikes," the ministry said in a statement under the name of a researcher at its research institute on Japan.

The ministry also voiced concerns that the focus of Japan's defense strategy could shift to an attack and invasion. (Yonhap)