In Nairobi, US Secretary of State Hillary Clinton, wife of the former president, sought to separate the humanitarian release from the nuclear talks.

'We have been working hard on the release of the two journalists, we have always considered that a separate issue from the effort to re-engage the North Koreans and have them to return to six-party talks and work to a commitment for the full, verifiable denuclearisation of the Korean peninsula,' she said.

'The future of our relations with the North Koreans is up to them. They have a choice. They can continue to follow a path that is filled with provocative action that further isolates them from the international community ... or they can decide to renew their discussions with partners in six-party talks,' she said.