Iran faces tougher sanctions: UK's Brown

LONDON (Reuters) - Iran faces tougher international sanctions if it chooses to "isolate itself from the international community" over its nuclear program, British Prime Minister Gordon Brown said Wednesday.

Foreign ministers from Britain, France, the United States, Germany, Russia and China meet in New York later Wednesday to discuss Iran's nuclear program.

Iran could join the international community if it honored 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 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.

The West suspects Tehran of seeking nuclear weapons, although Iran insists it only wants to generate electricity. It has defied five U.N. Security Council resolutions demanding that it suspend all sensitive nuclear activities.

Iran risked starting a nuclear race that Arab states might want to join, Brown said. "It is a very serious turning point for the world and we've got to make sure we take the right decisions," he said.

European Union foreign policy chief Javier Solana, who will join the six foreign ministers' for Wednesday's meeting, said on Tuesday he did not expect Russia and China to oppose Western powers if they called for new sanctions on Iran.

Brown also said he wouldn't shake hands with Iranian President Mahmoud Ahmadinejad if he runs into him at the General Assembly, where Ahmadinejad is also due to speak.

Ahmadinejad has caused international outrage by repeatedly calling the Holocaust a lie. Germany has said it will walk out of the U.N. General Assembly if Ahmadinejad denies the Holocaust in his speech Wednesday.

Iran has also angered Britain by putting an Iranian employee of Britain's Tehran embassy on trial on spying charges.

(Reporting by Adrian Croft; Editing by Jon Boyle)