Prime Minister Shinzo Abe lashed out at North Korea's firing Wednesday of a medium-range ballistic missile into the Sea of Japan, just days ahead of a key summit between the U.S. and Chinese leaders expected to focus on reining in Pyongyang's weapons programs.

The U.S. Pacific Command said it detected the launch at 6:42 a.m. from a land-based facility near Sinpo, home to a North Korean submarine base.

"(The launch) is a grave provocative action from a security standpoint, clearly violates U.N. Security Council resolutions and simply cannot be tolerated," Abe told reporters.