North Korea has lambasted the Japan-U.S. security alliance, labeling Tokyo "crafty" and claiming that Japan views tension on the Korean Peninsula as a "good opportunity" to loosen constitutional restraints on its military.

The remarks, in a commentary run by the North's official Korean Central News Agency, follow a military drill Tuesday that saw the nuclear-armed nation fire an intermediate-range missile over Hokkaido. The exercise — the first unannounced launch of a missile designed to carry a nuclear payload to fly over Japan — triggered global condemnation, including a strong response from Prime Minister Shinzo Abe, who called it an "unprecedented, grave and serious" threat.

In its commentary, the North blasted recent meetings with top U.S. officials that had focused on extended deterrence, missile defense and an enhanced role for Japan in the alliance. It also took Tokyo to task over a series of joint military exercises, including one in Hokkaido that wrapped up Monday, that it said were training for an invasion of the North.