Story highlights Japan's Abe warns that North Korean threat entering a new phase

China says will cooperate with UN action

(CNN) North Korea's nuclear ambitions are one of the biggest threats to international peace and security, Japanese Prime Minister Shinzo Abe warned Wednesday.

Speaking at the United Nations General Assembly in New York, Abe urged the Security Council to respond to the latest nuclear test "in a manner entirely distinct from our responses thus far."

'No alternative'

Japanese Prime Minister Shinzo Abe.

More than 21 ballistic missiles have been launched by North Korea this year alone, Abe said, with several of them reaching waters within Japan's exclusive economic zone -- 200 nautical miles from its coast.