Seoul Mayor Park Won-soon officially announced his candidacy for a third term Thursday, joining the ruling Democratic Party of Korea’s primary for the June local elections.

Park will compete against four-term lawmaker Park Young-sun and three-term lawmaker Woo Sang-ho for the party’s nomination.

The winner of the primary will run against former presidential hopeful Ahn Cheol-soo of the minor Bareunmirae Party and former Gyeonggi Province Gov. Kim Moon-soo of the main opposition Liberty Korea Party.

The incumbent mayor vowed to make Seoul a city where “ordinary people are happy” in a press conference at the ruling party’s headquarters Thursday.

“Six years ago, when the president (Lee Myung-bak) was digging rivers and building a wall of distrust, I became the mayor of Seoul and promised that I would become the first mayor who changes your life,” Park said.

“Now we have the Moon Jae-in administration which prioritizes people ... I would like to complete the 10-year revolution of making Seoul a city where ordinary people are happy.”

Park highlighted some of his policy achievements such as providing free school meals, halving tuition fees at a city-run university, reducing the city’s debt by 8 trillion won ($7.5 billion) and doubling its social welfare budget, as well as reviving run-down areas.

“Now, Seoul begins a new challenge for the future. Based on my six years of experience and capabilities in managing the city, I will improve the citizens’ quality of life and ensure the spirit of the candlelit square takes root in our democracy,” Park said, referring to the protests at the Gwanghwamun Square that led to the ouster of former President Park Geun-hye amid a corruption scandal last year.

The mayor pledged to make efforts to co-host next year’s National Sports Festival with Pyongyang, begin economic and cultural cooperation and exchanges with the North Korean capital, roll out a project to eliminate sexual violence and offer better support for the elderly and disabled.

Park is already the longest serving Seoul mayor.

The lawyer-turned-civic activist first ran as an independent in the mayoral by-election in late 2011, and then on the ticket of the Democratic Party three years later, with no primary.

Earlier Thursday morning, Park visited the Seoul National Cemetery to pay respects to fallen patriots.

He went to the grave of former President Kim Dae-jung to lay a wreath and burn incense.

On Wednesday, Park told city officials in an email that he would try to minimize the administrative vacuum during his campaign.

By Kim So-hyun (sophie@heraldcorp.com)