North Korea on Monday refused to give a firm commitment to taking part in the next round of six-party talks about its nuclear weapons programme, casting doubt on the prospect for any progress on the issue before the US presidential election in November.

Kim Gye-gwan, the country?s deputy foreign minister, told Bill Rammell, his British counterpart, that the regime was agreed in principle to continuing the talks, which involve the US and other powers in north Asia. But he could not give a date for this because of a ?souring of relations? with Washington.