Defense Secretary Chuck Hagel is calling North Korea's development of nuclear weapons a "growing threat" to the U.S. and its allies.
In a telephone call Tuesday evening to Chinese Defense Minister Chang Wanquan, Hagel cited North Korea's pursuit of nuclear weapons and ballistic missiles and said Washington and Beijing should continue to cooperate on those problems.
A Pentagon statement describing the phone call also disclosed that Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, will visit China later this month. It would be Dempsey's first trip to China as head of the Joint Chiefs. Hagel also invited the Chinese defense minister to visit the United States this year.