More than 8.64 million South Koreans cast ballots during the two-day early voting for the June 13 local elections, the election watchdog said Saturday.

The final turnout stood at 20.14 percent, as 8.64 million out of 42.90 million eligible voters participated in the early voting that ran through Saturday for the upcoming local elections slated for next Wednesday, according to the National Election Commission.

Up for grabs are 4,016 local administrative, legislative and educational posts, including 17 metropolitan mayors and provincial governors.

The turnout was the second highest ever after the early voting for the presidential election in May last year, when a record high proportion of the electorate, 26.06 percent, cast early ballots.

During the early voting for the local elections in 2014 and 2016, 11.49 percent and 12.19 percent of voters, respectively, took part in early voting, according to the NEC.

Turnout for this time was the highest in South Jeolla Province with 31.73 percent, and the lowest in the traditionally conservative city of Daegu with 16.43 percent, according to the NEC. In the capital city of Seoul, 19.10 percent of voters were found to take part in the early voting.

As for the advanced voting for this year's by-elections to fill 12 vacant parliamentary seats, the turnout came to 21.07 percent, the watchdog noted.

President Moon Jae-in and the first lady, Kim Jung-sook, also cast their ballots on Friday, joined by a number of senior secretaries.

The early voting system was introduced in April 2013 to encourage more to exercise their due rights.

Officials said holiday-goers would take advantage of the procedure, as the government designated the election day as a temporary national holiday.

The NEC expects the results to herald a higher overall turnout, as the higher early voter turnout, the higher the final one.

The upcoming elections are widely seen as an indicator of voter sentiment toward the incumbent leader, with recent polls showing that the ruling Democratic Party is taking a sizable lead in both elections on the back of strong public support for President Moon and his peace drive toward North Korea.

Experts also say a much-awaited summit between US President Donald Trump and North Korean leader Kim Jong-un slated for Tuesday could be a boon for the liberal DP, as the meeting is to take place just one day before the local polls.

But the ruling party had revved up efforts to encourage more voters to take part in the early voting out of concerns that citizens, particularly young voters, may skip the polls on the assumption that the DP will win by a large margin.

The main opposition Liberty Korea Party had made the same call, but out of different calculations that the early voting would help minimize the impact of the Trump-Kim meeting on the elections.

The LKP is still reeling from low public support following last year's ousting of former President Park Geun-hye over a massive corruption scandal.

On Saturday, candidates launched all-out campaigns throughout the country to win the hearts and minds of the people.

Ruling party leader Choo Mi-ae visited Daegu and North Gyeongsang Province, which have long been regarded as a stronghold for conservative candidates, and appealed for support.

"You, the people in Daegu, can usher in changes and a new era," Choo said, calling for the destruction of the regionalism that has long been a source of conflict in Korean politics.

In a move to unify its traditional supporters, LKP leader Hong Joon-pyo came to the southern port city of Busan and asked for their "staunch backing to make headway at this difficult time." (Yonhap)