South Korea's main opposition party leader Lee Jae-myung said Friday that Seoul should consider a joint investigation with Washington over the leakage of US intelligence documents that Seoul believes may have been fabricated.
The Yoon Suk Yeol administration's "attempted cover-up" of the controversy translates into a diplomatic humiliation, with which it "would defend neither sovereignty nor the national interest," said Lee, chairman of the Democratic Party of Korea, at a party gathering.
"Now is not the right time for Seoul to walk on thin ice (so as not to upset) Washington," Lee said.
"As a sovereign nation, Korea need to ask the United States for an apology, demand the truth and request a (Seoul-Washington) joint investigation to the US."
The opposition party also called on Yoon to settle the matter before his summit with US President Joe Biden takes place.
The leakage came weeks before the scheduled Seoul-Washington summit, at which Yoon is to make a state visit to the US to hold talks with Joe Biden. It will be the first such trip by a Korean leader in 12 years.
Seoul contends that most of the leaked classified US documents had been altered, and that there is no indication that the US conducted surveillance on private conversations here with malicious intention. Seoul, however, has yet to provide evidence to support this.
The documents were allegedly leaked by US airman Jack Teixeira of the Massachusetts Air National Guard. He was arrested Thursday.
Formerly a presidential election contender defeated by Yoon, Lee is an outspoken politician who is currently facing a number of charges in Korea. Allegations against him range from involvement in a high-profile land corruption scandal to false statements during the presidential campaign, as well as coercion of bribery of a third party. Lee has denied all the charges.
Lee attended a hearing Friday at the Seoul Central District Court over an alleged election law violation concerning a false statement meant to deny a personal connection with a key figure in a land corruption scandal who died by suicide in December 2021.
