Former Irish President Mary Robinson and former Norwegian Prime Minister Gro Harlem Brundtland are expected to travel to North Korea with former U.S. President Jimmy Carter, diplomatic sources said Thursday.

Carter plans to visit the communist nation in about a month to broker rapprochement in relations between Washington and Pyongyang, according to a diplomatic source in Washington. Former U.N. Secretary-General Kofi Annan and other prominent figures are expected to travel with him, the source said.

Sources in Seoul said Carter's delegation is also expected to include Robinson and Brundtland.

"I understand that former President Carter plans to visit North Korea with former heads of state-level figures with the aim of contributing to promoting peace on the Korean Peninsula," a source said.

All known members of the delegation – Carter, Annan, Robinson and Brundtland – are members of "The Elders," a group comprising 12 former heads of state-level figures.

Carter is considered a symbolic figure on the Korean Peninsula nuclear and peace issues.

He built his image as a peacemaker and a troubleshooter when he visited North Korea in 1994 amid intensifying nuclear tensions, and met with then leader and national founder Kim Il-sung.

His negotiations led to a landmark nuclear disarmament deal between Pyongyang and Washington, known as the Agreed Framework, though the agreement later fell apart with the outbreak of another nuclear standoff in late 2002.

Carter last visited Pyongyang in August 2010 on a mission to bring home a U.S. citizen detained in the communist nation for illegal entry. But he could not meet with leader Kim Jong-il at the time as Kim traveled to China during Carter's visit. (Yonhap News)