UN Secretary General Ban Ki-moon on Thursday urged a return to talks with North Korea, during a visit to South Korea that has fueled speculation of his presidential ambitions in his home country.

UN Secretary General Ban Ki-moon on Thursday urged a return to talks with North Korea, during a visit to South Korea that has fueled speculation of his presidential ambitions in his home country.

"We must find the path back to dialogue," Ban said at a peace and security forum on the southern island of Jeju.

Tensions between North and South Korea have been running high since Pyongyang conducted a fourth nuclear test in January.

In recent weeks, the North has made repeated proposals for military talks aimed at de-escalating the situation -- but the South has dismissed the offer as an "insincere" propaganda ploy.

The current administration of South Korean President Park Geun-Hye is adamant that substantive inter-Korean talks can only begin once the North makes a tangible commitment to denuclearization.

"The rise in tensions on the Korean peninsula could cast a shadow across Northeast Asia and beyond," Ban warned.

"I welcome all efforts to move forward. And I stand ready to personally contribute in any way that might be helpful", he added.

Ban has actively pursued an invitation to North Korea, and such a trip had been arranged to coincide with a visit to the South last November -- but the plan fell through.

Speaking to journalists in Jeju on Wednesday, Ban said the "window for a high-level dialogue" had been left open.

"I am the only one that has been maintaining a dialogue channel with Pyongyang," he added.

A North Korea visit would offer Ban a high-profile platform should he consider throwing his hat into South Korea's 2017 presidential race after stepping down as UN chief at the end of this year.

Ban has declined to confirm a run at the Blue House, although on Wednesday he offered what was seen as a broad hint in that direction, saying he would "contemplate ...what I should do as a South Korean citizen" after leaving the UN.

While calling for dialogue with the North, Ban also urged the international community to forcefully implement tough UN sanctions imposed on Pyongyang over its latest nuclear test.

North Korea's pursuit of nuclear weapons and ballistic missiles "only undermines its own security and hurts its citizens," he said Thursday, urging Pyongyang to "cease any further provocations."