Britain, France and Germany struck an agreement with Iran in November to suspend all uranium enrichment-related activities in return for talks on trade, security and technological bonuses for the Islamic Republic.
The talks had begun in Brussels in December, moved to Geneva in January and are to resume Tuesday in Geneva, diplomats said.
Political directors from the foreign ministries of the European trio are to attend, with Iran also sending a senior delegation and the European Union sending a technical expert from Brussels, diplomats said.
The talks are deadlocked as Britain, France and Germany are now calling on Iran to totally dismantle its nuclear fuel program in order to guarantee it does not seek atomic weapons, according to confidential reports obtained by
Iran insists its nuclear program is a strictly peaceful effort to generate electric power.
The United States, however, has complained to the EU about centrifuge-related work by Iran that could be used to make nuclear weapons and may violate the uranium enrichment freeze, diplomats said.
A European diplomat who asked not to be named said the Europeans needed to have the United States join in the talks since trade incentives, such as helping Iran join the World Trade Organization (WTO), were impossible without US backing.
But, said the diplomat, the Americans want to "torpedo the process" since they are convinced the Iranians are secretly developing nuclear weapons and seek confrontation with Tehran rather than accomodation.