Updated

The top U.S. diplomat for East Asia says the U.S. intends to deploy a missile defense system in South Korea "as soon as possible" to counter the threat from North Korea despite opposition from China.

Assistant Secretary of State Daniel Russel says that he believes South Korea is firmly committed to the deployment of the Terminal High Altitude Area Defense, or THAAD, system. Russel told a congressional hearing Tuesday the system is purely defensive and is not aimed at China but at North Korea.

The plans have complicated South Korea's efforts to foster warmer ties with China. Beijing says the system's radar could reach into Chinese territory.

Seoul and Washington began formal talks on THAAD earlier this year. Russel did not specify when the deployment would happen.