Russia urged North and South Korea Wednesday to start talking again, saying better relations are crucial to regional stability.

"Russia confirmed its support for inter-Korean dialogue and pointed out that dialogue between North and South Korea is a key factor in ensuring regional peace and stability," according to a joint statement issued by Seoul's presidential office.

Cross-border relations have been icy since the South accused the North of a deadly torpedo attack on one of its warships in March, a charge which Pyongyang denies.

The statement was issued as Russian President Dmitry Medvedev and President Lee Myung-Bak held talks in Seoul in advance of a G20 summit Thursday and Friday.

Russia is a member of a six-nation forum on the North's nuclear disarmament which also includes the two Koreas, the United States, China and Japan.

The North walked out of the talks in April 2009 and staged its second nuclear test a month later.

It has indicated conditional willingness to return, but Seoul and Washington say it must first show seriousness about disarming and improving cross-border relations.

The two sides agreed on the importance of solving the nuclear issue "comprehensively, completely, and irreversibly" and called on all sides to honour a six-nation aid-for-disarmament pact reached in September 2005.

They agreed to cooperate closely "to create an atmosphere conducive to the resumption of the six-party talks."