Many in the West suspect the controversial program of covertly seeking to acquire nuclear weapons, a claim Iran has consistently rejected.
Javier Solana and Ali Larijani, head the influential Supreme National Security Council, last met September 10 in Vienna, where the sides said some progress was made on a series of issues.
On September 14, experts from Iran and the EU met to discuss Iran's atomic research program in Geneva.
Under a UN Security Council resolution, Tehran was to have suspended uranium enrichment by August 31 as a precondition for further talks on a package of incentives that six negotiators on Iran's program -- Russia, the United Kingdom, China, France, the United States and Germany -- worked out in June.
Tehran's response to those incentives was handed to the Iran-6 group August 22. According to media reports, Iran claims it will consider suspending its uranium enrichment program only after talks.
However, the vice president of the Iranian National Atomic Energy Organization, Mohammad Saeedi, said Tuesday that Larijani and Solana will not discuss Tehran's moratorium on uranium enrichment.
Some countries propose drafting sanctions against Iran in the event talks fail. But Russian President Vladimir Putin said Monday after a meeting with the leaders of France and Germany, that the leaders are committed to a diplomatic resolution of the Iranian nuclear issue.
Russian Foreign Minister Sergei Lavrov earlier said he sees a number of constructive aspects in Tehran's response, and that these aspects help maintain contacts between Solana and the Iranian side.
The UN Security Council adopted Resolution 1696 July 31, demanding that Iran suspend uranium enrichment by August 31 or face possible economic and diplomatic sanctions. However, an International Atomic Energy Agency report said Tehran refuses to suspend the program and bars inspectors from its nuclear facilities.
Russia, which signed the UN resolution, opposes the imposition of sanctions advocated by the United States. Washington is pushing for a sanctions deadline, regardless of skepticism from Russia, China and even its European allies.
French President Jacques Chirac advocates the continuation of dialogue, saying last week he opposes setting a deadline for sanctions, and that talks should be allowed to run their course.
Russia is helping Iran build the plant at Bushehr, 400 kilometers (250 miles) southwest of the capital, Tehran. The NPP is being constructed under the supervision of the International Atomic Energy Agency, the UN's nuclear watchdog.
Iran's vice president and head of the Atomic Energy Organization, Gholamreza Aghazadeh, arrived in Moscow Monday to discuss the plant with Sergei Kiriyenko, the head of Russia's Federal Nuclear Power Agency.
As a result, Russia and Iran signed Tuesday a supplementary agreement on the delivery of 80 metric tons of nuclear fuel in March 2007.
Russia's nuclear power equipment and service export monopoly, Atomstroiexport, is building Bushehr's first power unit under a $1 billion contract signed by Russia and Iran in 1995. A supplemental agreement signed in 1998 stipulates that Atomstroiexport will complete construction of the plant on the basis of a turnkey arrangement.
However, the fuel will be delivered no later than six months prior to the plant's commissioning, set for September 2007, according to Sergei Shmatko, the Atomstroiexport head.
Kiriyenko, who is also a co-chairman of a Russian-Iranian intergovernmental commission, is set to visit Iran in December.
