Russian and Iranian negotiators ended a day of talks on Monday without a breakthrough, but agreed to continue negotiations on Moscow's offer to enrich uranium for Tehran on Tuesday.

Following today's meeting, the office of presidential Security Council Secretary Igor Ivanov, who hosted the Iranian delegation, issued a short statement that the two sides had agreed to continue talks. The statement did not say where the negotiations would be held or what time they would start.

The Russian offer to enrich Iran's uranium on Russian soil without giving Iran the technology was widely seen as the last chance for Iran to address the West's concerns before a March 6 meeting of the U.N. nuclear watchdog, the International Atomic Energy Agency, which could start a process leading to sanctions by the U.N. Security Council.

Meanwhile in Brussels, Iranian Foreign Minister Manouchehr Mottaki insisted his country would press ahead with nuclear research even if it accepts the Russian proposal.

"If we reach some compromise ... [on the Russian proposal], we continue our cooperation from where we are now. That is, the research department will continue its activity," Mottaki said after meeting with EU foreign policy chief Javier Solana.

Speaking after the meeting, Solana said Iran's "substantive position has not changed. They have to be much more constructive."

Before the talks began, a Russian official said he had limited hopes that anything significant would come from the meetings.

"Honestly speaking, we have modest expectations, but we will make every effort to avoid an escalation of the situation and the use of force," Russian Foreign Minister Sergey Lavrov told a government meeting chaired by President Vladimir Putin in televised comments shortly before the talks began.

The Iranians have blown hot and cold over Moscow's initiative, under which Iran's enrichment activities would take place on Russian soil to ensure no uranium is diverted for nuclear weapons. Enrichment is a process that can produce either fuel for a nuclear reactor or material for a warhead.

The Russian foreign minister said Iran could conduct all nuclear activities on its own soil once the IAEA had resolved its concerns about the Iranian nuclear program.

Lavrov said last week the Russian proposal is conditional on Iran giving up all enrichment activity, including small-scale efforts it started last week. The EU and the United States also insist that Tehran reimpose a freeze on all enrichment.

Analysts said a concrete result likely would emerge from further talks later in the week, when the head of Russia's atomic energy agency, Sergei Kiriyenko, visits Iran.

Experts have said Iran would like its scientists to have access to the Russian enrichment facility and hope to retain the right to conduct part of the enrichment process at home. But former Russian Atomic Energy Minister Viktor Mikhailov told the Vremya Novostei daily in Monday's editions that the entire facility would be off-limits to the Iranians.

IAEA chief Mohammed ElBaradei recently suggested that the international community might have no choice but to accept small-scale enrichment on Iranian soil as a condition for Tehran to agree to move its full program abroad, a diplomat familiar with ElBaradei's position said Sunday on condition of anonymity because of the sensitivity of the issue.

Iranian presidential spokesman Gholamhossein Elham, speaking in a news conference Monday, welcomed the IAEA proposal on small-scale enrichment inside Iran as a "positive step" toward resolving the dispute but said any restrictions on Tehran's right to access nuclear energy were unacceptable.

The Associated Press contributed to this report.