The United States does not exclude other countries' contributions in the negotiations between the 'Six' and Iran, U.S. State Department spokesman Philip Crowley said at daily briefing.
"We don't rule out any role for any particular country, but obviously the P-5+1 is the core group, and we expect next month's to revolve around that same group," Crowley said, answering a question on the any other contribution from Turkey, beside hosting the talks as a country.
Another round of talks on the Iranian nuclear issue was over in Geneva on Tuesday. Deputy foreign ministers of Russia, the United States, Great Britain, China, France, Germany and EU High Representative for Foreign Affairs and Security Policy Catherine Ashton attended the talks. Iran was represented by Secretary of the Iranian Supreme National Security Council Saeed Jalili.
The sides decided to continue it in late January in Istanbul.
The negotiating process was broken in 2009 when the IAEA Board of Governors condemned Iran for building the second plant to enrich uranium and called on Tehran to confirm that no decisions were made on the construction of other nuclear facilities, not declared by the agency.