Moscow (Xinhua): Russian President Dmitry Medvedev has said the nuclear issues of both Iran and North Korea are different and Pyongyang's activities have raise more concerns than that of Tehran.

"I believe that the situation, say, in Iran and North Korea are different ... We are closely watching nuclear programmes in these countries," Interfax news agency quoted Medvedev as saying Saturday.

The president said Russia was ready to assist the US in establishing closer and sincere relations with Iran.

Additional sanctions "can only complicate the situation if they are introduced now", Medvedev was quoted as saying by Itar-Tass, referring to the proposal to impose sanctions against Iran over its alleged crackdown on election protests.

Medvedev said he was more concerned about the situation in Pyongyang "because Iran communicates with the international community, but North Korea has now practically severed all of its contacts".

The group of six parties, which has been involved in talks on the Korean peninsula nuclear issue, "is not active at the moment", he said.

"We should seek ways and approaches to get our North Korean colleagues to communicate," he said, adding that there is no alternative to dialogue with the communist country.