"Seoul's diplomacy with China has collapsed due to the decision to deploy the Terminal High Altitude Area Defense (THAAD) system," said Park Jie-won, the party's floor leader, adding that Pyongyang is taking advantage of the situation to revitalize its ties with Beijing.
Beijing and Moscow have been criticizing the deployment, adding the move will disrupt the regional stability and hurt their strategic interests.
"This proves that THAAD gives no benefit to the national interest," Park also said, adding the deployment will also speed up the military tension between Washington and Beijing, which will eventually be harmful to world peace.
The People's Party also criticized the main opposition party for not expressing criticism against the deployment.
The country's opposition has failed to find common ground when it comes to THAAD.
Kim Chong-in, the interim leader of the Minjoo Party of Korea, has remained neutral on the move, and said he does not object to the anti-ballistic missile system's deployment here, although some lawmakers have urged Kim to join hands with other opposition parties to help stop the deployment. (Yonhap)