BEIJING, July 8 (Xinhua) -- China has said it is "strongly dissatisfied" by U.S. plans to deploy a missile defense system in the Republic of Korea (ROK), warning that the move may destabilize the Korean Peninsula.

The ROK Defense Ministry announced on Friday that the ROK and the United States had decided to deploy a U.S. THAAD anti-missile system.

"The Chinese side is strongly dissatisfied with and firmly opposes this," China's Foreign Ministry said in a statement.

The deployment is not conducive to denuclearization of the Peninsula nor to maintaining peace and stability, according to the ministry.

It said the move goes against efforts to calm regional tension, and severely harms the security interests of countries in the area including China, as well as the "strategic balance" in the region.

China urged the United States and ROK to terminate the deployment of THAAD, and not to take any action which may complicate the regional situation and harm China's interests.

Also Friday, China's Ministry of National Defense voiced similar stance.

"We will closely watch the moves of the United States and the ROK, and will consider taking measures to safeguard the nation's strategic security and the strategic balance in the region," said Yang Yujun, spokesman for the Ministry of National Defense.