MOSCOW — The North Korean leader, Kim Jong-il, has agreed to consider a moratorium on nuclear weapons tests and production, and said he would return to stalled six-party talks on the nation’s nuclear program, the Russian presidential press secretary told the Russian news media on Wednesday.

Mr. Kim made the agreement at a meeting with President Dmitri A. Medvedev in the southern Siberian city of Ulan Ude, where he is stopping on a weeklong trip in his armored train.

“They confirmed their willingness to go back to the negotiations without preconditions,” the press secretary, Natalya Timakova, said after the meeting.

“In the course of the talks, North Korea will be ready to resolve the question of imposing a moratorium on tests and production of nuclear missile weapons,” she was quoted as saying.