SEOUL (BLOOMBERG) - North Korea has labelled Moon Jae-in a meddlesome mediator and reduced to rubble a US$15 million (S$20 million) liaison office that was one of the South Korean president's biggest diplomatic achievements.

On Monday, however, Kim Jong Un's regime abruptly restored communication with South Korea via hotlines that Pyongyang had let fall silent for about two months. The move came after Kim's sister praised Moon as a man of admirable ideas.

The change in tone likely has a lot to do with the political calendar in Seoul. South Korea elects a new president in March and time is running out for Moon to make good on one of his core pledges to bring the two Koreas closer to peace. North Korea sees the election as a chance to win concessions from Moon and get him to press the United States to do the same.

"It appears that North Korea's strategy for now is to work through South Korea," said Rachel Minyoung Lee, a nonresident fellow with the 38 North Programme at the Stimson Centre. "It is pressuring Seoul to not walk in lockstep with Washington's North Korea policy and to persuade the Biden administration to offer concrete incentives to North Korea."

The restoration of the hotlines - established in 2018 after a series of historic summits between Kim and Moon - comes as Pyongyang dangles the prospects of another face-to-face meeting before the South Korean leader leaves office. The summit would discuss matters such as the formal end to the 1950-53 Korean War, which Moon urged anew during an address to the United Nations last month.

South Korean Unification Minister Lee In-young told Yonhap News Agency he saw the restoration of the communications links as marking a "restart" in efforts to improve ties.

A summit - perhaps on the sidelines of the Winter Olympics in Beijing in February - would provide a timely boost for Moon's progressives, who have long backed engagement with North Korea. Public opinion polls suggest the conservative People Power Party has a shot at winning office.

Kim, meanwhile, has been looking to rally domestic confidence as North Korea faces one of its worst food shortage in years. He is struggling to build an economy that has shrunk since he took power about a decade ago after being hit with global sanctions to punish Pyongyang for defying UN resolutions by testing nuclear weapons and missiles that can deliver warheads.

While North Korea has frequently shifted between provocations and diplomatic overtures, Kim now appears to be trying to do both at the same time. The regime has in recent months restarted activity at its plutonium-production site and fired off several new weapons systems designed for strikes against Japan and South Korea, which host the bulk of US troops in Asia.

If successful, Kim's appeal to Moon could have the added benefit of widening gaps between Washington and a key ally. Kim may be seeking to increase his leverage if he returns to nuclear-disarmament talks with the US, which have been stalled for more than two years.

The Biden administration has told North Korea the door is open for talks and has indicated it could offer incentives in exchange for nuclear disarmament steps. But Pyongyang dismissed the overture as a "petty trick".

Kim Yo Jong, the North Korean leader's sister who has led pressure campaigns against Seoul and Washington, praised Moon's recent call for peace as an "interesting and an admirable idea". About two weeks earlier, she had denounced his criticism of North Korea's weapons tests as foolish.

South Korea has little power to actually bring about a peace treaty after it refused to sign the armistice among US-led UN forces, North Korea and China that ended the Korean War's fighting. America has talked about a peace deal and diplomatic recognition as something that would follow an agreement to dismantle North Korea's nuclear arms program.

For Moon, that wait may be too long.

"Pyongyang is taking advantage of Moon's desperation to leave behind a Korean peace legacy before March by dangling hopes to make Seoul work harder to satisfy the regime and break from Washington," said Duyeon Kim, an adjunct senior fellow in Seoul with the Center for New American Security. "The mood in the Moon government is 'all hands on deck' to make sure an end-of-war declaration is signed by the four heads of state at the Beijing Olympics when they start in February."