Three former world leaders will accompany ex-US president Jimmy Carter to North Korea this month to discuss tensions on the peninsula and food shortages in the communist state, a report said Monday.

JoongAng Daily, quoting diplomatic sources in South Korea, said Carter would be accompanied by former Finnish president Martti Ahtisaari, former Irish president Mary Robinson and former Norwegian prime minister Gro Harlem Brundtland.

The four are members of a group of ex-leaders known as The Elders. The group said on its website it was concerned at high inter-Korean tensions and the reported food shortages.

"A small group of Elders is considering a visit to the region at the end of April to discuss with officials and others how these issues may be addressed," the weekend statement said, adding that plans were not finalised.

Seoul's foreign ministry said nothing had been confirmed about such a visit.

Widespread media reports say Carter will pay a three-day trip to Pyongyang starting April 26.

Carter, president from 1977-81, visited the North in 1994 after Washington came close to war with Pyongyang over its nuclear weapons programme.

In talks with then-leader Kim Il-Sung, he helped negotiate a deal under which the North shut down its reactor in return for energy aid.

Last August the 2002 Nobel peace prizewinner visited Pyongyang to secure the release of jailed US citizen Aijalon Mahli Gomes.

The US-North Korean "Agreed Framework" agreement broke down in 2002 and a subsequent six-nation deal reached in 2005 has also collapsed.

Carter was quoted last week as saying he would try to revive the six-party talks and address humanitarian woes.

United Nations food agencies who recently visited the North say more than six million people -- a quarter of the population -- urgently need food aid.

Tension has been high on the peninsula since the North's alleged sinking of a South Korean warship in March 2010. Last November it shelled a South Korean island and killed four people.

Last November the North also disclosed an apparently functional uranium enrichment plant, giving it a potential second way to make atomic bombs even though it says the uranium programme is peaceful.

South Korea's nuclear envoy Wi Sung-Lac will visit the United States from Tuesday to Thursday to discuss the enrichment programme and ways to revive the six-party talks, a Seoul foreign ministry spokesman said.

Wi will meet his US counterpart Sung Kim as well as US special envoy for North Korea Stephen Bosworth.

Efforts by Washington and Seoul in February to address the uranium programme at the UN Security Council failed amid opposition from Beijing, Pyongyang's strong ally.

The possible resumption of food aid to the impoverished North will be on the agenda as well, Yonhap news agency said.