The United States expects Iran' s nuclear program to be the leading issue discussed when talks resume on Dec. 5 between Iran and the five UN Security Council permanent members and Germany (P5+1), U.S. State Department spokesman Philip Crowley said Friday.

"You know, we expect that the nuclear program will be among or will be the leading issue discussed," Crowley told reporters at a press briefing at the department.

Iran proposed Nov. 23 or Dec. 5 as the date for planned talks with the six major powers in Istanbul, but Iranian President Mahmoud Ahmadinejad said Iran will not discuss its nuclear issue in the proposed talks.

European Union foreign affairs chief Catherine Ashton has proposed to meet Iran's chief nuclear negotiator Saeed Jalili on Dec. 5, probably in Switzerland, turning down Iran's suggestion of venue.

Crowley said the venue is still to be determined and "a more central location" is preferred for the first meeting.

"Istanbul could still be a location for a second, a follow-on meeting, but the general consensus is that the first meeting should be somewhere in central Europe," Crowley added. "We've had the previous meeting in Geneva. That seemed to be a location that, you know, satisfied the travel arrangements for all members of the P5+1."

Talks in Geneva broke down in October 2009. In May this year, Iran challenged the West countries with a proposal brokered by Turkey and Brazil, but met with cold-shoulder. A fresh round of sanctions was slapped on Tehran one month later by the UN Security Council and unilateral actions by the U.S. and several other countries.

Iran insists that its nuclear program is for civilian use, while the West countries say it is a guise for developing nuclear bombs.