Japan is pressing fellow participants in six-party talks on North Korea’s nuclear programme not to allow Pyongyang back into negotiations unless it reiterates last year’s commitment to remain a non-nuclear state.

Taro Aso, foreign minister, was expected to spell out Japan’s position when he met Ban Ki-moon, South Korea’s foreign minister, in Tokyo on Sunday. Nicholas Burns, US undersecretary for state, will be told the same in a round of meetings with senior Japanese officials on Monday.