The United States and Japan agreed Thursday to speed up deployment of a missile defense system amid growing concerns about North Korea's weapons development, a Japanese government official said.

The agreement came at a meeting between U.S. Secretary of State Condoleezza Rice and Japanese Foreign Minister Taro Aso at the Asia-Pacific Economic Cooperation forum in Hanoi, Vietnam, the official said.

"There was a general consensus among us ... it's urgent for my country to accelerate this deployment of a ballistic missile defense system," the official said on condition of anonymity, citing policy.