The ruling and opposition parties are clashing over a move to subject the deployment of the THAAD missile defense system to parliamentary ratification.

The floor leader of the ruling Democratic Party of Korea revealed the party would back Cheong Wa Dae’s possible push to delay the Terminal High Altitude Area Defense deployment in interviews with local media.

The party currently holds 120 seats in the 299-seat parliament.

“The National Assembly’s push to subject the issue to parliamentary ratification and to analyze the issue carefully will be of great help to the administration in negotiating with the US,” Rep. Park Yong-jin, the Democratic Party’s deputy floor leader, said Thursday.

The party has also issued a statement that the possibility of withdrawing from the deal and returning THAAD to the US should be considered if any irregularities are found in the previous administration’s actions on the related issue.

“The new Cabinet will thoroughly investigate the installation process with the defense, environment, and foreign ministries, and will promote parliamentary hearings to clear suspicions surrounding the process,” said a special panel of the party Thursday.

Key components of the THAAD battery, such as the radar and interception missile launchers, were delivered to the site of Seongju, North Gyeongsang Province in April.

The main opposition Liberty Korea Party and the minor conservative Bareun Party, however, remain firmly behind the THAAD deployment. Both parties consider parliamentary ratification unnecessary.

“It would be pointless to hold large-scale parliamentary meetings over every decision made to protect the country,” said Rep. Kim Sun-dong, floor leader of the Liberty Korea Party.

The Democratic Party has also come under fire from the People’s Party, which demands that the ruling party must first make its position on the THAAD deployment clear before discussing parliamentary procedures.

On the other hand, the presidential office has made its position clear. It was most recently reaffirmed by President Moon Jae-in’s special envoy to the US, Hong Seok-hyun.

During his visit to Washington, Hong told reporters of the brewing controversy over the THAAD deployment and the necessity to place it under parliamentary supervision.

The special envoy reported that the THAAD deployment was not discussed with US President Donald Trump, but with national security adviser H.R. McMaster in separate talks.

Meanwhile, Cheong Wa Dae has revealed that it is focusing on establishing a fresh diplomatic foundation with the US through a bilateral summit in June, rather than rushing into renegotiation.

An official from Moon’s administration said, “It’s diplomatically unfavorable for South Korea to choose a definite position ahead of the summit.”

The president and his aides have expressed regret over the previous government’s decision to deploy THAAD.

Trump has said Seoul should pay $1 billion for the anti-missile system, however, under the South Korea-US Status of Forces Agreement, Seoul was to provide the land and related facilities for the system while the US would pay for its operation and maintenance costs.

By Jung Min-kyung (mkjung@heraldcorp.com)