President Yoon Suk Yeol has accepted the resignation of Defense Minister Kim Yong-hyun, who is believed to have advised Yoon to declare martial law, according to presidential Chief of Staff Chung Jin-suk on Thursday.

At a briefing Thursday morning, Chung said Yoon has approved Kim's dismissal from the post, without clarifying when his approval was made.

Yoon tapped Choi Byung-hyuk, a retired four-star Army general who is currently the ambassador to Saudi Arabia, as the new Defense Minister nominee to replace Kim, Chung added.

Chung declined to take questions from reporters.

Earlier on Wednesday, Kim said in a text message to reporters that he had offered to resign, saying he was the one responsible for the mobilization of armed forces in South Korea.

On the same day, the Ministry of Defense confirmed that Kim had proposed that Yoon declare martial law at an extraordinary Cabinet meeting Tuesday night, just before Yoon's declaration.

The main opposition Democratic Party filed a motion to impeach Kim at 5:45 p.m. Wednesday and tabled the motion Thursday.

Lawmakers of the minor opposition Rebuilding Korea Party filed a complaint with police against Kim on Wednesday as it accused Kim of insurrection, along with President Yoon.

Before the announcement, the National Assembly had sought to summon Kim for questioning at an emergency defense committee meeting scheduled for 10 a.m.