SEOUL -- South Korea's ruling party leader on Monday announced his resignation after President Yoon Suk-yeol was impeached by the parliament last Saturday.

Han Dong-hoon, leader of the People Power Party, said in a televised press conference that he resigned as the party's supreme council collapsed with the resignation of its members, making it impossible for him to carry out his duties as the party leader.

He apologized to all the people who suffered from the imposition of an emergency martial law, which was declared by Yoon on the night of Dec. 3 but was revoked by the National Assembly hours later.

Han made best efforts to find a better way for the country except Yoon's impeachment, but it failed, noted Han, who earlier pushed for an "orderly resignation" of Yoon.

Han's resignation came less than five months after he was elected as the party leader on July 23.

The second motion to impeach Yoon was passed through the National Assembly on Saturday and was delivered to the constitutional court to deliberate it for up to 180 days, during which Yoon's presidential power is suspended.

Following the impeachment, all five elected members of the People Power Party's supreme council expressed their willingness to step down.

With Han's resignation, floor leader Kweon Seong-dong will serve as acting leader of the ruling party.