Iran vowed to pursue its disputed atomic programme come what may, reducing the chances that talks today with the European Union would avert US pressure for tougher international sanctions against the Islamic Republic.
Iranian Foreign Minister Manouchehr Mottaki said late last night that nothing would deflect the Islamic Republic from its pursuit of nuclear technology and that Washington had "lost" in its attempts to stop them.
"The Iranian nation will never return from the path that they have chosen and they are determined and decisive to continue this path (to obtain nuclear technology)," Mr Mottaki was quoted as saying by the official IRNA news agency.
If there is no progress at today's talks in London, six world powers due to meet in Paris on Saturday will try to agree new penalties to propose to the UN despite differences in their approach to halting Irans's nuclear programme.
The West says the programme is aimed at building atom bombs and wants a freeze on its enrichment of uranium. Iran, a major oil exporter, says enrichment efforts are meant only to produce electricity which it says is an inalienable right.
Attempts by the six nations - Britain, China, France, Germany, Russia and the United States - to stall Iran's programme have failed and they vowed to pass a new UN Security Council resolution if there was no progress by December.
The five permanent members of the Security Council plus Germany plan to draft a new resolution imposing wider financial, trade and visa restrictions to increase pressure on Tehran to stop enriching uranium, which can be used in atomic bombs.
But diplomats and analysts say Iran will see little reason to suspend uranium enrichment given that the six powers remain at odds over how soon to resort to more United Nations penalties, or how harsh they should be.
Russia and China, and to a lesser extent Germany, have close commercial ties to Iran and are likely to tailor their new sanctions proposals accordingly, taking a less hawkish approach than that of the United States, Britain and France.
"America is angry with Iran over its nuclear programme but they know that the cost of attacking Iran will be very high," Mottaki told a gathering of the Basij religious militia. "America has lost in its nuclear challenge with Iran."
Tehran said earlier this week that Iran's chief nuclear negotiator Saeed Jalili would put forward "new initiatives" to European Union foreign policy chief Javier Solana in London on Friday, without giving further details.