China reiterated on Tuesday its resolute opposition to the deployment of a US anti-missile defense system in the Republic of Korea after the system's first components arrived in the peninsula.

The ROK's National Defense Ministry said Seoul had begun assembling the Terminal High Altitude Area Defense system after part of its battery section was delivered, Xinhua News Agency reported.

"We've noticed the development. China will resolutely take necessary measures to defend its security interests, and all the consequences of that will be borne by the United States and the ROK," Foreign Ministry spokesman Geng Shuang said at a daily media briefing in Beijing.

He urged the parties concerned to stop the deployment process and not to go too far down the wrong path.

The deployment could be completed in a month or two, and the defense system could be operational as early as April, according to the ROK's Yonhap News Agency.

"The deployment of THAAD has little meaning in protecting the ROK. Instead, it will pose a threat to China's strategic security because its radar could cover parts of China," said Shi Yongming, a researcher at the China Institute of International Relations.

Wang Junsheng, a researcher in Northeast Asia studies at the Chinese Academy of Social Sciences, said the insistence of the US and ROK in deploying the system was not conducive to regional peace and stability.

Wang said the China-ROK relationship may experience a cooling period due to the deployment. "The ROK has to suffer whatever consequences are caused by it," he said.