Yoon Suk-yeol, the presidential election candidate of South Korea's main opposition People Power Party (PPP), attends his election campaign in Seoul, South Korea, March 1, 2022.
Yoon Suk-yeol, the presidential election candidate of South Korea's main opposition People Power Party (PPP), attends his election campaign in Seoul, South Korea, March 1, 2022. Reuters / KIM HONG-JI

South Korea's two main presidential candidates are in a tight race a week before a March 9 vote, with the last days of the campaign dominated by Ukraine and by gaffes that critics say highlight both contenders' lack of foreign policy experience.

Lee Jae-myung from President Moon Jae-in's ruling Democratic Party, will face off against Yoon Suk-yeol, of the conservative main opposition People Power Party in what some media have dubbed the "unlikeable election" due to the candidates' high disapproval ratings and smear campaigns.

A survey by Realmeter released on Wednesday, the last day for publication of polls under election rules, showed 46.3% of respondents favoured Yoon with 43.1% preferring Lee. Hankook Research on Sunday put them neck and neck on about 40% each.

Surveys show voters are looking for a president who can clean up polarised politics and corruption, heal a deepening social divide, and tackle runaway housing prices and widening inequality that have plagued Asia's fourth-largest economy.

Two-day early voting is set to begin on Friday.

"The top priority for most voters is the economy and housing prices but politically sensitive gaffes that occur right before the election could have an impact in a close race like this," said Shin Yul, a professor at Myongji University.

Neither old rival North Korea, which has recently resumed its missile tests, nor COVID-19, with unprecedented levels of infections topping 210,000 in one day for the first time on Tuesday, has proven to be a key issue.

The race has been overshadowed in recent days by Russia's invasion of Ukraine and by South Korea's decision to join international efforts to put pressure on Russia with sanctions.

Both Lee, a former provincial governor, and Yoon, a former prosecutor general, have suffered setbacks over comments deemed insensitive or inappropriate related to the Ukraine crisis.

On Friday, Lee came under fire after saying during a televised presidential debate that Ukrainian President Volodymyr Zelenskiy had "provoked" Russia by insisting on joining NATO.

"A novice politician with just six months experience became president and made a hasty promise on NATO admission, which provoked Russia," he said, calling it a "stark example of war resulting from diplomatic failure".

Lee was alluding to what he sees as Yoon's naivety and provocative attitude towards North Korea when suggesting an inexperienced and hotheaded leader could trigger war.

But his comment drew widespread criticism on social media and anger from Yoon who called it an "international disgrace" and said Lee was defending the aggressor in Ukraine instead of consoling the victim.

Some senior officials in Lee's party added fuel to the fire, referring to Zelenskiy as a "comedian-turned-amateur president with no leadership".

Lee eventually issued an apology to Ukrainians on Saturday, saying he did not mean to disparage Zelenskiy but to emphasise Yoon's security views. He said he wished for a peaceful solution to the war in Ukraine.

Days later, Yoon found himself in hot water after posting a "We stand with Ukraine" meme that critics said was frivolous and Lee said was a "disgrace".

The incidents were the latest in a series of scandals and controversies that have dogged both candidates and they raised concern over both candidates' lack of foreign policy experience, Shin said.

Touching on foreign policy issues without proper historical understanding and diplomatic consideration could backfire on either side, he added.

Both Lee and Yoon were scheduled to hold video meetings with Ukraine's ambassador-designate in South Korea, Dmytro Ponomarenko, on Wednesday.