South Korea's liberal presidential candidate Lee Jae-myung said on Monday he would pursue the restoration of communications between Seoul and North Korea, including via a military hotline if elected.

The two Koreas have in the past communicated using hotlines but Pyongyang had stopped responding since 2023 amid a sharp deterioration in ties between the neighbours.

Lee, who is the front-runner in opinion polls for the June 3 election, also said in a Facebook post that he would "stably manage" relations with China, which he said had reached the "worst state" under the previous administration.

He vowed to develop the US-South Korea relationship into a comprehensive strategic alliance and respond in principle to past historical and territorial issues related to Japan while strengthening cooperation between South Korea, the United States and Japan.

Advisers to Kim Moon-soo, Lee's main conservative election rival, said Lee's proposals had much in common with Kim's pledge to strengthen the alliance with Washington and keep doors open for dialogue with Pyongyang.

Yet, Kim Gunn, a former nuclear envoy, and one of Kim's foreign policy advisers, criticised Lee for changing his policy direction in what he saw as a bid by the candidate to appeal to more moderate voters.

Another adviser Kim Hyung-suk, a former vice unification minister, also said Lee’s promises did not address North Korea’s serious nuclear threat but only sought to re-engage with the isolated state.

"So I think that regarding the pledges laid forth by Mr Lee, we will have to see if he can put them into action," Kim Gunn told a meeting with the foreign press on Monday. (Reuters)