Former president Mary Robinson has joined former US president Jimmy Carter in North Korea on a mission to ease inter-Korean tensions.
They will also assess food shortages and try to revive the stalled nuclear disarmament talks.
The delegation, known as The Elders, also includes former Finnish president Martti Ahtisaari and former Norwegian prime minister Gro Harlem Brundtland.
The group has said it hopes to meet leader Kim Jong-Il and Kim's son and heir apparent Jong-Un, although nothing has been arranged.
North Korea's official news agency announced their arrival in a one-sentence report but gave no details.
The delegation was in China beforehand and will go on to South Korea on Thursday.
Efforts to improve North-South relations are deadlocked, with the North refusing to accept blame for two deadly border incidents last year.
Six-party talks on the North's nuclear disarmament have been stalled since December 2008, and Pyongyang formally quit the forum in April 2009 and staged its second nuclear weapons test a month later.
Late last year the North disclosed a uranium enrichment plant, giving it a potential second way to make atomic bombs and lending renewed urgency to efforts to restart negotiations.
The North's persistent food shortages will also be a key topic, after UN food agencies estimated that 6m people - a quarter of the population - urgently needed aid.
Mr Carter said yesterday: 'It is a horrible situation there and we hope to induce other countries to help alleviate (the food crisis), including South Korea, which has cut off all supplies of food materials to North Koreans.
'When there are sanctions against an entire people, the people suffer the most and the leaders suffer the least.'
Mr Carter first visited Pyongyang in 1994 for talks with founding President Kim Il-Sung after the US and North Korea came close to war over the communist state's nuclear weapons programme.
He visited again last August to secure the release of a detained US citizen but did not meet Kim Jong-Il.