South Korean President Yoon Suk Yeol apologized for his attempt to impose martial law this week but did not resign, defying intense pressure to step down even from some in his ruling party and only hours ahead of a planned impeachment vote.

Yoon said he would not seek to avoid legal and political responsibility for his decision to declare martial law for the first time in South Korea in decades. He said the decision was born of desperation and also promised not to make another attempt to impose martial law. 

Yoon's speech was the embattled leader's first public appearance since he rescinded the martial law order early on Wednesday, just six hours after it was declared, after parliament defied military and police cordons to vote against the decree.

"I am very sorry and would like to sincerely apologize to the people who were shocked," Yoon said in a televised address to the nation, during which he bowed.

WATCH | An end to Yoon's presidency?: 

Aborted martial law in South Korea 'probably heralds the end of Yoon's presidency': analyst

Jeremy Chan, senior analyst for China and Northeast Asia at Eurasia Group, says South Korean President's Yoon Suk Yeol's tenure is likely at risk after lawmakers including members of his own party unanimously rejected his declaration of martial law. Yoon's term was set to end in 2027, but he is likely to face direct impeachment articles in the coming weeks, Chan says.

"I leave it up to my party to take steps to stabilize the political situation in future, including the issue of my term in office," he added.

Han Dong-hoon, leader of Yoon's People Power Party (PPP), said after the addres the president was no longer in a position to carry out his public duties and that his resignation was now unavoidable.

On Friday, Han said Yoon was a danger to the country and needed to be removed from power, increasing the pressure on him to quit even though PPP members later reaffirmed a formal opposition to his impeachment.

Han was scheduled to meet Prime Minister Han Duck-soo on Saturday, local Yonhap News reported. Under the constitution if Yoon resigns or is impeached then the prime minister, who was appointed by Yoon, becomes South Korea's interim president.

Lawmakers have now began a meeting to vote on the main opposition Democratic Party's motion to impeach Yoon.

It remained unclear ahead of the vote as to whether the impeachment motion will obtain the support of two-thirds of lawmakers it needs to move forward.

Lee Jae-myung, the leader of the Democratic Party, told reporters that Yoon's speech was "greatly disappointing" and the only way forward is his immediate resignation or impeachment.

A shock to the nation

Yoon shocked the nation late on Tuesday when he gave the military sweeping emergency powers in order to root out what he called "anti-state forces" and overcome obstructionist political opponents.

Some PPP members urged Yoon to resign before the vote, saying they did not want a repeat of the 2016 impeachment of then-president Park Geun-hye, who left office following months of candlelit protests over an influence-peddling scandal. Her downfall triggered the implosion of the party and a victory by liberals in presidential and general elections.

In scenes reminiscent of those protests, thousands of demonstrators holding candles assembled outside parliament on Friday night demanding Yoon's impeachment.

More demonstrations are expected on Saturday during the vote.

Prosecutors, the police and the Corruption Investigation Office for High-ranking Officials have all launched probes into Yoon and senior officials involved in the martial law decree, seeking to pursue charges of insurrection and abuse of power, among others.

The officials face potential charges of insurrection, abuse of authority and obstructing other people from exercising their rights. If convicted, the crime of leading an insurrection is punishable by death or life imprisonment, with or without prison labour.