North Korea criticized a joint military exercise by South Korea, Japan and the United States held this month, state media said on Sunday, saying such drills show the relationship among three countries has developed into "the Asian version of NATO."

On Thursday, the three countries began large-scale joint military drills called "Freedom Edge" involving navy destroyers, fighter jets and the nuclear-powered U.S. aircraft carrier Theodore Roosevelt, aimed at boosting defenses against missiles, submarines and air attacks.

The exercise was devised at the three-way summit at Camp David last year to strengthen military cooperation amid tensions on the Korean peninsula stemming from North Korea's weapons testing.