The United Nations nuclear watchdog says it is unable to determine if Iran is trying to develop nuclear weapons, because Iran is still not fully cooperating with its probe.
The International Atomic Energy Agency (IAEA) says in a report "uncertainties" have not been cleared up despite three years of inspections. The agency board meets on March 6 to consider the report and decide on referring Iran to the U.N. Security Council, where it could face sanctions.
The agency report also says Iran is operating at least 10 centrifuges and carrying out small-scale uranium enrichment.
Russia has been trying to persuade Iran to stop enrichment activity, which the West believes is aimed at developing nuclear weapons. Iran said Sunday it reached a preliminary agreement with Russia to enrich uranium for Iran on soil.
But Japanese officials who met with Iran's foreign minister Monday say Iran has vowed not to suspend its nuclear program
Russia and Iran will meet again on Tuesday.
Sunday's deal between Russia and Iran was announced following a meeting in Bushehr between visiting Russian nuclear chief Sergei Kiriyenko and Iranian nuclear chief Gholamreza Aghazadeh.
The two officials said no formal agreement has yet been reached, and both said more talks are needed to resolve details.
Russia and Iran are trying to complete the deal before the meeting of the IAEA.
Some information for this report was provided by AFP, AP and Reuters.