Rival party lawmakers on the National Assembly’s Foreign Affairs and Unification Committee are criticizing the way the government handled what they called Japan’s halfhearted Sado mines memorial preparations, saying the incident was a diplomatic disaster for South Korea.

Ruling People Power Party lawmaker Yoon Sang-hyun said Thursday that Seoul had attempted to meet Tokyo halfway on historical issues but Japan failed to do its part.

He added that Japan also failed to keep its promises after another forced labor site, Hashima Island, was added to the UNESCO World Heritage list in 2015.

Main opposition Democratic Party lawmaker Han Jeoung-ae said that while the event was supposed to be a memorial for forced labor victims, in the end it was just a ceremony to celebrate the UNESCO inscription.

Opposition lawmaker Wi Sung-lac blamed the current administration for the incident, saying it was the result of the government’s long-standing policy toward Japan.

Before the session, Foreign Minister Cho Tae-yul apologized for the incident and said he would take full responsibility.