BEIJING -- China is "deeply concerned" over the decision by the United States and the Republic of Korea (ROK) to launch an official negotiation on the deployment of an advanced US missile defense system, called Terminal High Altitude Area Defense (THAAD), on the Korean Peninsula, a spokesperson said on Sunday.

"China holds a consistent and clear stance on the anti-missile issue," Chinese Foreign Ministry spokesperson Hua Chunying said.

"When pursuing its own security, one country should not impair other's security interests,"said the spokesperson.

Hua said moves to advance the deployment will escalate tensions on the peninsula, which will do harm to regional peace and stability, and set back efforts to address the current situation.

"We demand the countries concerned be prudent when handling the issue," Hua added.

According to the spokesperson, Chinese vice foreign minister Liu Zhenmin lodged representations over the ROK' s announcement of the decision and made clear China' s solemn position during an urgent appointment with ROK ambassador to China Kim Jang-soo.