Iran pledged to pursue its disputed atomic program as Europe's top diplomat met Tehran's main nuclear negotiator on Friday in a last effort to avert tougher sanctions.

Iranian Foreign Minister Manouchehr Mottaki said late on Thursday 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), Mottaki was quoted as saying by the official IRNA news agency.

The West says Iran's nuclear program is aimed at building atom bombs. Iran, a major oil exporter, says efforts to enrich uranium are intended only to produce electricity.

Diplomats and analysts say Iran will see little reason to relent in its refusal to suspend uranium enrichment given that six big powers remain at odds over how soon to resort to more United Nations penalties and how harsh they should be.

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.

But it said there will be no talk about suspension of nuclear fuel work, a key demand of the U.N. Security Council without which Iran will face a third, wider round of sanctions.

Jalili replaced Ali Larijani as chief nuclear negotiator in October. Close to Iranian President Mahmoud Ahmadinejad, he is seen by analysts as signaling a hardening of Iran's position.

America is angry with Iran over its nuclear program 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.

NOTHING HAS CHANGED

Ahead of the meeting, which began at 1000 GMT, a spokeswoman for Solana said that they had taken note of Mottaki's comments, adding: We have to see what Jalili says at the meeting.

A member of the Iranian delegation said they were positive about Friday's talks but did not elaborate. Solana's spokeswoman said he had no new proposals to make and wanted to hear whether Tehran had any new initiatives. Nothing has changed.

The five permanent members of the Security Council plus Germany agreed earlier that barring a positive outcome by November to both EU-Iran talks and a U.N. nuclear watchdog investigation of Iran, they would draft a new resolution imposing wider financial, trade and visa restrictions to increase pressure on Tehran to stop enriching uranium.

But 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.

They (Western countries) shouldn't make threats because threats make Iran more determined, former president Akbar Hashemi Rafsanjani told worshippers at Tehran University.

Rafsanjani, who is also the speaker of the powerful Assembly of Experts, said that Iran was cooperating with the International Atomic Energy Agency (IAEA), referring to an August agreement under which Tehran pledged to the Vienna-based body to clear up suspicions about past secret atomic activities.

Iran has barred inspections beyond uranium production sites since its case was referred to the U.N. Security Council in February 2006, fueling suspicions in the West that it has a covert parallel military nuclear program.

The IAEA sees wide-ranging, access to Iran's sites under its Additional Protocol with member states as key to verifying there is no such program.

Iran has no program to discuss the Additional Protocol at its parliament and Iran has no commitment regarding the implementation of the Additional Protocol, Mottaki said.

(Additional reporting by Adrian Croft in London and Zahra Hosseinian in Tehran)

(Editing by David Clarke and Dominic Evans)