UN tells Iran: sanctions are coming

As the jamboree quits New York, leaders leave Ahmadinejad in no doubt what will happen if he presses ahead with nuclear ambitions

Iran has been given an ultimatum to suspend its nuclear programme and warned it will face economic sanctions unless it makes a "serious response" by 1 October. At a special session of the United Nations Security Council yesterday which endorsed Barack Obama's vision of a nuclear-free world, six major powers issued a tough warning to Iran. There were also growing signs that Russia is moving in favour of new sanctions against Tehran.

The US, Britain and Germany want any expanded sanctions to squeeze Iran's vital oil sector because the country needs to import up to 40 per cent of its gasoline needs. Gordon Brown said Iran faced a "moment of truth". The country could either join the international community or face isolation.

Mr Brown said the six nations – the US, Britain, Germany, France , Russia and China – had sent the "strongest possible message" to Iran. Last night a Downing Street spokesman said the six countries would decide their next steps after they held talks with Iran in Istanbul on 1 October.

Nicolas Sarkozy, the French President, said dialogue with Tehran had not yielded results so far. "There comes a time when stubborn facts will compel us to take a decision if we want a world without nuclear weapons," he said. Dmitry Medvedev, the Russian President, meanwhile appeared to dilute Moscow's outright opposition to further sanction, saying they should be looked at if Iran proved obdurate on enrichment. "Sanctions are seldom productive but they are sometimes inevitable" he said.

China remains strongly opposed. "We believe that sanctions and exerting pressure are not the way to solve problems and are not conducive for the current diplomatic efforts on the Iran nuclear issue," said Jiang Yu, the Foreign Ministry spokeswoman.

No decision on detailed sanctions is likely before the end of the year and the next raft may be little more than symbolic. More Iranian firms and individuals could be added to existing UN blacklists for asset freezes and travel bans established in three previous rounds of sanctions.

The six UN powers want Iran to shelve its uranium enrichment programme and allow UN inspectors to verify it has no covert project to develop nuclear weapons. In return, the Islamic Republic would qualify for trade, technology and diplomatic benefits.

Iran issued a defiant response, warning that talks would be successful only if "illegal demands" were dropped. Its UN mission said: "We believe that as a prerequisite for success in future negotiations, futile and illegal demands of the past years that have proven to be of no avail should be abandoned."

Mahmoud Ahmadinejad, the Iranian President, did not mention the nuclear issue in his address to the General Assembly. But US and British officials walked out after he accused Israel of "inhuman policies".

The Security Council special summit also unanimously approved a resolution calling on nuclear-weapons states to scrap their arsenals. It was the first time a US President has chaired a Security Council meeting since it was formed in 1946.

Mr Obama told the summit,which marked a big shift in US policy on disarmament, that the spread and use of nuclear weapons was "a fundamental threat to the security of all peoples and all nations". The resolution, drafted by the US, called for "further efforts in the sphere of nuclear disarmament" and urged all countries that have not signed the 1970 nuclear Non-Proliferation Treaty (NPT) to do so.

Mr Obama's predecessor George Bush angered many NPT members by ignoring disarmament pledges made by previous US governments. Yesterday's resolution also called for an end to the proliferation of atomic weapons and demanded that parties to the NPT keep their promises not to develop atomic warheads.