Ministers from Iran, six powers meet to end impasse in nuclear talks

(Reuters) - The foreign ministers of Iran and six world powers met on Monday in a final push for a preliminary accord less than two days before their deadline to outline a deal to end Tehran's nuclear standoff with the West.

For days Iran, the United States, Britain, France, Germany, Russia and China have been holding marathon negotiations in the Swiss city of Lausanne to break an impasse in nuclear negotiations, but officials cautioned that attempts to reach a framework accord could yet fall apart.

In addition to U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif, British Foreign Secretary Philip Hammond, French Foreign Minister Laurent Fabius, Germany's Frank-Walter Steinmeier, Russia's Sergei Lavrov and China's Wang Yi gathered at a 19th-century hotel overlooking Lake Geneva to try to end the deadlock in the talks.

The six powers want more than a 10-year suspension of Iran's most sensitive nuclear work. Tehran, which denies it is trying to develop a nuclear weapons capability, demands in exchange for limits on its atomic activities a swift end to international sanctions that are crippling its economy.

While some issues being discussed in the negotiations have been resolved, there are several differences on which the two sides have been unable to reach agreement. Both Iran and the six have floated compromise proposals in an attempt to make an accord possible.

One sticking point concerns Iran's demand to continue with research into newer generations of advanced centrifuges that can purify uranium faster and in greater quantities than the ones it currently operates for use in nuclear power plants or, if very highly enriched, in weapons.

Another question involves the speed of removing United Nations sanctions on Iran. A senior U.S. official said on Sunday there were other unresolved issues, but expected those would fall into place if the big sticking points could be worked out.

Even if Iran and the six powers reach an agreement by their end-March deadline, officials close to the talks say it could still fall apart when the two sides attempt to agree on all the technical details for a comprehensive accord by June 30.