Extra edition newspapers with the top headline "President Yoon Suk Yeol's impeachment passed" are seen at Seoul Station on Saturday. (Yonhap)

The opposition-led National Assembly on Saturday approved a motion to impeach President Yoon Suk Yeol on charges of insurrection tied to his botched declaration of martial law on Dec. 3, making him the third South Korean leader to be suspended from his duties by the parliament.

With the impeachment resolution delivered to Yoon later in the evening, he was suspended from office immediately, until the Constitutional Court decides whether to reinstate or formally oust him following a deliberation process that could take up to 180 days. Prime Minister Han Duck-soo is to serve as the acting leader of the country in the meantime.

Han told reporters that he would "give his best efforts and strength to achieve stable management of state affairs," as he entered Government Complex Seoul following the passage of the motion.

After the bill was passed, President Yoon released a statement, vowing he would "not give up" and "do his best for the country" until the end.

The motion, which marks the second of its kind to be introduced by the opposition coalition against Yoon, passed in a 204-85 vote, with three abstentions and eight invalid votes. It met the quorum of 200 votes in the 300-member parliament during the plenary meeting that kicked off at 4 p.m.

Assembly Speaker Woo Won-shik lauded the outcome of the vote, saying it was a "decision brought on by the desperation, bravery and dedication for democracy portrayed by the people."

The lawmakers of the main opposition Democratic Party of Korea bowed in unison at the main building of the Assembly, while stressing that "this is just the beginning" of the move to resolve the political turmoil triggered by the martial law decree.

"The passage of the impeachment motion is the glorious victory of our people," Democratic Party Floor Leader Park Chan-dae said on behalf of his party.

"The Dec. 3 insurrection case has yet to be concluded. The suspension of insurrection mastermind Yoon Suk Yeol's power is merely the first step toward resolving the (current situation)," he added. Park said that the opposition will "not let their guard down" until the ongoing investigations into Yoon and others charged with insurrection conclude.

People Power Party Chair Han Dong-hoon said while he accepts the outcome of the vote with a "heavy heart," he has no plans to resign. He pledged to "right all wrongs" and "protect the Constitution and democracy" throughout the remainder of his term as head of the party.

Minutes before Saturday's plenary meeting convened, the ruling People Power Party announced the party line to vote against the opposition-led motion, but added that it would not boycott the vote. The decision, announced by its new Floor Leader Rep. Kweon Seong-dong, came after more than five hours of intense debate during the party's first general meeting of lawmakers, which kicked off in the morning. Lawmakers were heavily divided on the notion of changing the party line to vote in favor of the motion.

A total of seven People Power Party lawmakers had expressed their intention to vote in favor of the impeachment motion in the days leading up to Saturday's plenary vote.

All but three of the 108 ruling party lawmakers boycotted the first impeachment vote against Yoon on Dec. 7, which led to the motion being automatically rejected, as it fell short of the required 200-vote quorum.

Hundreds of thousands of protesters who called for Yoon's impeachment outside the Assembly in western Seoul cheered as Speaker Woo Won-shik announced the outcome of Saturday's vote.

The Constitutional Court's deliberation process took around 90 days for former President Park Geun-hye's impeachment from late 2016 to early 2017. Park was ultimately removed from office after the court's unanimous 8-0 vote in March 2017.

Yoon is now the third South Korean president in constitutional history to face impeachment. The Assembly passed an impeachment motion against President Roh Moo-hyun in 2002 and later against President Park Geun-hye in 2016. The Constitutional Court ousted Park, but reinstated Roh to power.