The United States is negotiating with China on a possible stronger U.N. Security Council response - such as new sanctions - to North Korea's repeated ballistic missile launches, which the 15-member body normally condemns in a statement, diplomats said.
It was not immediately clear how open Beijing might be to new sanctions. The council has traditionally boosted sanctions in response to North Korea's five nuclear tests and two long-range rocket launches.
Sanctions were first imposed on Pyongyang in 2006.
