China warned Thursday that the possible deployment of an advanced U.S. missile defense system in South Korea could undermine the "overall interest of bilateral relations" between Seoul and Beijing, underscoring a long-standing rift between the neighbors despite their growing warmth on bilateral ties.

The warning by China's foreign ministry spokesman Hong Lei came a day after China's defense minister Chang Wanquan held talks with South Korean Defense Minister Han Min-koo in Seoul on Wednesday, during which Chang expressed concern over Washington's plan to deploy its Terminal High-Altitude Area Defense battery in South Korea.

Asked about the rare public concern by the Chinese defense chief over the possible deployment of the THAAD battery in South Korea, Hong replied, "We believe that countries should bear in mind the security interest of other countries as well as regional peace and stability in the pursuit of its own security."

"We hope that the relevant country will properly deal with this issue in the overall interest of peace and stability of the whole region as well as the overall interest of bilateral relations,” Hong said.

South Korea has officially disavowed its intention to join or host the THAAD battery, but the U.S. has said it was considering deploying the advanced missile-defense system to South Korea, home to about 28,500 American troops, to better cope with growing threats of North Korea's nuclear and missile capabilities.

China's opposition to a deployment of the THAAD battery in South Korea has been well known. However, this week's public remarks by Chinese officials, including the defense minister, again proved how it is difficult for South Korea and China to develop common security interests in Northeast Asia.

If the THAAD battery is deployed in South Korea, Chinese experts have said it would also allow the U.S. military to monitor long-range missile activity deep inside mainland China.

In spite of international sanctions, North Korea continues to pose security threats to Northeast Asia and beyond, by developing its nuclear and ballistic missile programs.

North Korea, which has conducted three nuclear tests since 2006, has threatened to conduct a new nuclear test in response to a U.N. resolution condemning its human rights violations.

South Korea and the U.S. have called on China to play a greater role in leading North Korea to give up its nuclear weapons, but Beijing's diplomacy still appears to put its priority on stability, rather than the denuclearization of North Korea.

(Yonhap)