"We express deep regrets over the government unilaterally proceeding with the deployment of THAAD without going through the legitimate process of reaching a public consensus," the resolution said.

It, in particular, pointed to Article 60 of the Constitution that stipulates the National Assembly has "the right to consent to treaties pertaining to any restriction in sovereignty or treaties which will burden the state or people with an important financial obligation."

The government, however, claims that the THAAD installation does not require a new treaty as it can proceed under already existing arrangements with Washington that already went through the parliamentary ratification process.

Criticizing Beijing for its retaliatory steps that have hurt South Korea's tourism, cosmetic and other industries, the resolution said those steps are "inappropriate and irrational" and would hurt the South Korea-China relationship that has deepened since the establishment of their diplomatic ties 25 years ago.

The Assembly's committee on foreign affairs will deliberate on the resolution to determine whether to send it to a plenary session for a vote.

Earlier this month, the US began deploying THAAD components to the peninsula. The installation, which is expected to be complete as early as next month, comes amid Pyongyang's continued provocations such as ballistic missile launches and a high-thrust rocket engine test.

Beijing has opposed the deployment, saying THAAD's powerful radar could be used to monitor its military activities. However, Seoul has said the deployment is a necessary self-defense measure to cope with Pyongyang's evolving military threats. (Yonhap)