The second-ranking U.S. diplomat will travel to Vietnam, Cambodia and Hong Kong next month.

The State Department said Wednesday that Deputy Secretary of State John Negroponte's Sept. 10-18 trip will be an opportunity to deepen U.S. engagement in an increasingly dynamic region.

The trip announcement comes as the United States accuses North Korea of violating disarmament commitments by suspending disablement work on its nuclear reactor.

North Korea is angry over what it sees as Washington's failure to act on a key promise in nuclear talks to remove it from a U.S. list of terrorism sponsors. The U.S. says the North must first agree to a plan to verify its nuclear declaration before being removed from the terror blacklist.