The United States intends to deploy the THAAD missile defense system to South Korea "on an accelerated basis" and "as soon as possible," given the ever-growing missile threats from North Korea, the top US diplomat on Asia said Tuesday.

Assistant Secretary of State Daniel Russel made the remark during a hearing before the House Foreign Affairs Subcommittee on Asia and the Pacific, stressing it's important to upgrade defensive systems to cope with the North Korean threats.

"I can't speak as assistant secretary of state to the timeline."

"Perhaps, our colleagues in the Defense Department and the Republic of Korea can. But given the accelerating pace of North Korea's missile tests, we intend to deploy on an accelerated basis, I would say, as soon as possible," Russel said in response to a question if THAAD can be deployed by next year.

Asked if he believes THAAD's deployment in South Korea is "a done deal," Russel said, "Yes, I do."

Russel also stressed it's a defensive system aimed only at coping with the North Korean threats.

"This is a defensive measure aimed not at China, but at North Korea. It is a defense based decision, not a political decision.

And it is part of a layered system of defense that will augment many military installations and systems currently in place," he said. (Yonhap)