Former US President Jimmy Carter has described his meeting last week with a top North Korean official as "negative and confrontational" and marked by condemnation of past US policy.
Carter, who visited the communist state with three other ex-leaders, also criticised the North's military-first priorities in a report on the visit.
The ex-leaders, from a group called The Elders, intended to ease heightened tensions between the two Koreas, assess food shortages and encourage nuclear disarmament.
Carter, in a report posted on the Carter Center website, said they also hoped to persuade the North to work with the United Nations on human rights and to free an American detained since last November.
The North says it will charge Eddie Jun Yong-Su with unspecified crimes against the nation. Carter confirmed earlier reports that Jun, a tractor salesman, also acts as a missionary.
Carter said a meeting with nominal head of state Kim Yong-Nam was "surprisingly negative and confrontational, filled with his condemnation of historical US policy toward North Korea".
The ex-president said he finally interrupted to point out that Kim "was concentrating exclusively on a negative and distorted picture of the past while we had come to look to the future with hopes of reconciling differences".
But the meeting ended with no easing of tensions and Kim said Jun would not be released.
The group failed to meet leader Kim Jong-Il. But they said they received a personal message from him that offered unconditional talks with the United States and South Korea including a summit with Seoul's leader.
Foreign Minister Pak Ui-Chun described the North's "great need" for food aid and peace and stressed commitment to past denuclearisation accords, Carter wrote.
"He made it plain, however, that NK would have to retain nuclear weapons as long as they are threatened by an antagonistic US with nuclear weapons."
Carter was criticised by South Korean media for his perceived pro-Pyongyang bias. But in his report he questioned the North's priorities after visiting a large hospital with no running water except in the operating room area.
"We saw no reason why a government that can develop advanced weapons cannot provide water for their hospitals," he wrote.
The Elders after their trip described the North's food shortages as a crisis. Carter accused the US and South Korea of a "human rights violation" for, in his view, withholding food aid from the North for political reasons.© ANP/AFP