North Korea’s leader Kim Jong-il has held rare talks with Russian President Dmitry Medvedev on Pyongyang’s nuclear programme and economic co-operation.
Mr Kim said his country was ready to discuss ending nuclear tests if six-party talks on denuclearisation resumed, Russian media reported.
The pair also discussed plans for a pipeline that would pass through the North’s territory to South Korea.
There has been no official comment so far from North Korea.
The Russian gas company, Gazprom, has reportedly been working for years on the deal for the pipeline, which would stretch more than 1,700km (1,000 miles).
South Korean media reports that the deal could be worth up to $100m (£60m) annually in transit handling fees for the impoverished North.
But the BBC’s Lucy Williamson in Seoul says it would also give Pyongyang de facto control over a key energy supply to the South, and without a major step forward in relations on the peninsula, that is likely to make some in Seoul very nervous.