China is preparing all necessary measures, including diplomatic and military responses, to South Korea's planned deployment of an advanced US anti-missile system on its soil, a former Chinese diplomat and expert on Korean affairs said Thursday.

Yang Xiyu, a senior research fellow at the China Institute of International Studies, emphasized that there will be "no winners" in the arms race, such as the deployment of the Terminal High Altitude Area Defense system (THAAD) in South Korea.

He served as head of the Chinese foreign ministry's office dealing with Korean Peninsula issues in the mid-2000s and was involved in the now-suspended six-party denuclearization talks.

"We understand South Korea's concerns well, but it is bringing in a tug-of-war between major powers into its own territory without knowing it," Yang said during a seminar held at a university in Suwon, south of Seoul. "This is like playing a part of the US' global missile interception system."

"It would be strange not to take any action in response. China is making various preparations, including diplomatic and military ones," Yang added. He, however, did not elaborate on what countermeasures Beijing is considering.

South Korea and the US announced a plan in July to deploy THAAD by end-2017, saying it would counter the growing military threat from the North. China strongly opposes the move, expressing worries that it is part of the US missile defense system that would hurt its strategic security interests.

Yang said that if Korea goes ahead with its deployment plan, it would end up hurting both the global and the regional "strategic balance," and "stability," adding there will be "no winners in this game."

He also repeatedly called the THAAD deployment a part of a decadeslong arms race in the region that he said has not contributed at all to regional stability.

"South and North Korea both have engaged in an arms race for the past two decades, but do you think that has helped bring in stability? The answer is absolutely no. Things have been less stable than two decades ago," he said. "It's time to stop the arms race and start thinking about how to cut down spending on weapons for the sake of genuine security."

As for North Korea and its nuclear issue, Yang said that China wants the denuclearization of the whole Korean Peninsula, while raising the need for the resumption of the six-party talks aimed at making Pyongyang give up its nuclear ambitions.

The multilateral denuclearization talks involving the two Koreas, the United States, China, Japan and Russia have been stalled since late 2008, when the North walked away from the negotiating table.

"The international community has an obligation to resolve the North's nuclear issue, and it has to pursue not only pressure and sanctions but also clear guarantees (for its security) within a reasonable and fair frame," he said.

"The problem is that there is no such frame now with emphasis being placed only on sanctions against the North," he added.

"Ignoring a serious threat to the North's security is not just avoiding due responsibility but also making it hard to find a way to denuclearization."  (Yonhap)