Moon Jae In, of the liberal Democratic Party of Korea, won South Korea's presidential election Tuesday.

Moon, a 64-year-old former chief of staff to the late President Roh Moo Hyun, got 41.08 percent of the vote, leading his two main rivals by a comfortable margin.

Hong Joon Pyo of the conservative Liberty Korea Party and Ahn Cheol Soo of the centrist People's Party conceded defeat.

"I humbly accept the people's choice," Anh said, while Hong said, "I accept this election's outcome."

The National Election Commission is expected to formally announce the winner of the snap election at around 10 a.m. on Wednesday, after which he will be immediately sworn in as president to serve a full five-term, without any transition period.

Final voter turnout was tentatively put at 77.2 percent with some 32 million out of 42 million eligible voters having cast their ballots.

"I hope today becomes the day to open the door for a new Republic of Korea," Moon told a crowd of jubilant party officials and supporters after visiting the party's main office, while asking them to await the official results.

Moon also said that if he indeed becomes president, succeeding Park Geun Hye who was removed from office earlier this year over a corruption and abuse-of-power scandal, he will do his best "to enact reform programs and achieve national unity."

Park, who was the country's first female leader, was imprisoned in March after being thrown out of office, and her ouster has left the country deeply divided between those who supported and opposed it.

Many analysts had viewed Moon, who calls for a more reconciliatory stance on North Korea and seeks reform of family-controlled business conglomerates called "chaebol," as the clear favorite to win the election, which was held seven months earlier than originally scheduled because of Park's ouster.

The incoming president will have to tackle several issues such North Korea, the sluggish economy and deeply rooted corruption.

The election comes at a time of heightened tensions on the Korean Peninsula following Pyongyang's repeated ballistic missile tests and concerns that it may conduct a sixth nuclear test, in defiance of U.N. Security Council resolutions.

Moon has been under criticism from conservatives who view him as soft on North Korea and worry that his election victory might benefit North Korea and cause strained relations with the United States.

He has decried Park's hawkish stand on North Korea and also criticized her decision to deploy an advanced U.S. antimissile system, known as Terminal High Altitude Area Defense, which has led to strained relations with China.

Regarding relations with Japan, Moon has repeatedly called for renegotiation for a bilateral agreement the two governments reached in 2015 on dealing with the issue of comfort women forced into Japanese military brothels before and during World War II.

In line with the terms of the deal, the Japanese government disbursed 1 billion yen ($8.9 million) last year to a South Korean fund to help former comfort women and their families.

But the two governments continue to be mired in a diplomatic row over comfort women statues erected by civic groups outside Japan's embassy in Seoul and its consulate in Busan, which led Japan to recall its ambassador to South Korea for three months in retaliation.

The Japanese government has called on the new South Korean government to fully implement the 2015 agreement to "finally and irreversibly" resolve the comfort women issue.

Prime Minister Hwang Kyo Ahn, who has been serving concurrently as acting president since Park's impeachment, decided not to run in the election.