The recent decision by South Korea and the United States to deploy an advanced missile defense system on the peninsula is part of "self-defense" efforts against evolving nuclear and missile threats from North Korea, Seoul's top diplomat said Monday.

Foreign Minister Yun Byung-se also said in his speech at the National Assembly that the country will take every possible measure in the face of the North's continued pursuit of weapons of mass destruction.

"At a time when the North is upgrading its nuclear and missile capacity and publicly expressing its intention for a nuclear strike, (the decision) is a self-defense action aimed at protecting our national security and life," Yun told lawmakers.

"Going forward, the government will take every possible measure to cope with the North's nuclear and missile capacity," he added.

On Friday, South Korea and the United States announced that the countries have agreed to deploy the Terminal High Altitude Area Defense missile interception system in order to upgrade the military allies' defense against North Korea's nuclear and missile capabilities.

Exactly when and where the missile systems will be placed has not been disclosed yet.

China and Russia have explicitly expressed opposition against the THAAD deployment in South Korea on concerns that the move could hurt their strategic security interests.

North Korea's military issued a warning earlier in the day that it will deliver military strikes from the moment the two countries decide on where to place the THAAD system in South Korea.

Yun said that the Seoul government has explained to China and Russia that THAAD is not aimed at a third country and that it has no intention of hurting their strategic security interests.

"The government has communicated with other neighboring countries on this matter whenever there was a chance," Yun said, adding that he will keep working to emphasize Seoul's rationale behind the THAAD deployment. 

Yun underlined the importance of forming a unified front on dealing with issues with diplomatic and national security ramifications, calling for bipartisan support from the political circles for the THAAD deployment.

Political parties have been divided over THAAD, with smaller parties expressing worries over negative fallout from its deployment and impact on Seoul's relations with China and Russia.

"I think that nothing is more important than internal understanding and unity to overcome challenges," Yun said. "We ask for bipartisan understanding and cooperation from the National Assembly."  (Yonhap)