North Korea has criticized South Korea and the U.S. for participating in a naval drill last week with Japan.
Held last Tuesday through Thursday, their navies trained in stopping the proliferation of weapons of mass destruction.
Pyongyang's propaganda website Uriminzokkiri said Monday that the U.S. joining in the drill, in view of the Singapore declaration, was a provocation.
The website said North Korea is trying to build peace and harmony, and accused Washington is being contradictory in promising to improve their relationship while at the same time participating in a drill that targets the North.