NEW YORK (AFP) - Russia will keep working for a political solution on Iran, a top Russian diplomat said Wednesday, as the Kremlin kept the West guessing whether it will back calls for further sanctions on Tehran. In our opinion, today the question should not be 'sanctions or not sanctions, but how to find a political solution to end this problem, said Sergei Kislyak, the Russian Ambassador to the US and former negotiator on Iranian nuclear issues. There is a chance for that and we will work at it, he told AFP. Today the priority is to start a serious dialogue with the Iranian partners on how to resolve this situation, said Kislyak, Russias former deputy foreign minister. Our position has always been flexible. The only question is, what the priorities of the international community are. But Kislyak refused to say whether Russia would support a call by the West to slap more sanctions on Tehran over its refusal to halt uranium enrichment and rein in its suspect nuclear programme. Meanwhile, British Prime Minister Gordon Brown said Iran faces tougher international sanctions if it chooses to isolate itself from the international community over its nuclear programme. Iran could join the international community if it honoured the commitments it had made, Brown said in a BBC radio interview from New York, where he is due to address the United Nations General Assembly later on Wednesday. But if it chooses to isolate itself from the international community, then the action that we have got to take will have to be stepped up. That means there will have to be more sanctions against an Iran that refuses to accept its responsibilities, he said. Iranian Foreign Minister Manouchehr Mottaki, meanwhile, Tuesday renewed Tehrans refusal to discuss its suspect nuclear programme and urged the US to work for a compromise, a Japanese official said. Mottakis comments came in talks with his Japanese counterpart Katsuya Okada on the sidelines of this years UN General Assembly, a Japanese government official said. Iranian people respect dialogue, but we are not willing to hold negotiations on our rights, Mottaki told Okada, according to the official, who spoke to reporters on condition of anonymity. In an interview on Wednesday, French Foreign Minister Bernard Kouchner said he was not in favour of plans mooted by some US lawmakers to impose fuel sanctions on Iran to make it come clean on its nuclear programme. I think this is a bit dangerous, Kouchner told the International Herald Tribune. Kouchner, speaking in New York, where he is attending the United Nations General Assembly, warned that a fuel blockade would harm the Iranian people, and mainly poor people. Meanwhile, a report said China is potentially undermining US-led efforts aimed at curbing Irans nuclear ambitions by supplying the Middle Eastern state with petrol. Citing unnamed traders and bankers, the Financial Times said state-owned Chinese oil companies were selling the petrol through intermediaries and now accounted for a third of Tehrans gasoline imports. It added that the sales are legal because the current sanctions do not cover fuel imports.