Iran agrees to allow inspections of a recently revealed nuclear facility near the city of Qom... 2009

President Mahmoud Ahmadinejad (hand raised)

Saeed Jalili, Iran's chief nuclear negotiator, met the UN Security Council's five permanent members plus Germany for talks in Switzerland, with the possibility of a rare bilateral meeting between Iran and the US.

The meeting in Geneva came a week after the disclosure of a second Iranian uranium enrichment plant raised tensions over Tehran's nuclear ambitions.

Iran had said its nuclear programme was not up for discussion in the talks and would like to focus instead on regional security issues.

But Western diplomats hoped Iran would be willing to talk about its nuclear programme and the second enrichment facility, which the US, Britain and France revealed a week earlier.

If Iran was willing to address the nuclear issues, then there probably would be subsequent meetings, PJ Crowley, the US state department spokesman, said in Washington.

"That process will take some time," he said.

"We're not going to make a snap judgment on Thursday. We're going to see how that meeting goes, evaluate the willingness of Iran to engage on these issues."

Western powers were also keen to gauge Russian and Chinese reaction to previous week's announcement that Tehran had been concealing the uranium enrichment plant at Qom.

Iran said its nuclear programme was for peaceful purposes and had already defied five UN Security Council resolutions demanding it suspends all sensitive nuclear activities.

Speaking to Al Jazeera, John Large, an independent nuclear consultant, said: "It's quite a complex area to actually decipher whether the effort is going into a civilian programme or into a military programme.

"There are the associated industries like the missile delivery systems, the development of missiles, we have seen the launch this week of quite sophisticated missile delivery systems.

"So you're looking at all the jigsaw pieces coming into place and I'm afraid the conclusion that is coming out of this is that these jigsaw pieces mean that there is a strong weapons programme underway."

Mohamed El Baradei, the outgoing  head of the UN's nuclear watchdog, said on Tuesday that Iran was "on the wrong side of the law" by not declaring the second plant.

"Iran was supposed to inform us on the day it was decided to construct the facility," he said.

Iran declared the facility only after it had been revealed by Western intelligence agents.

Washington expressed its willingness to hold one-on-one meetings with Iranian negotiators, a move that comes alongside a possible softening in Iran's approach.

According to Iranian state-run news agencies, Mahmoud Ahmadinejad, the Iranian president, announced in Tehran that Iran would be willing to fuel Iran's nuclear facilities with uranium purchased from a third party country.