The UN Secretary-General, Kofi Annan, has ended a trip to Iran with little apparent progress over its controversial nuclear programme.
Mr Annan, who had talks with President Mahmoud Ahmadinejad, said Iran was prepared to discuss its uranium enrichment programme but would not suspend the work before negotiations.
He also said that Iran had reaffirmed its commitment to support the UN resolution on Lebanon.
Mr Annan met the Iranian President and the country's supreme leader, Ali Khamenei, today on the second day of his visit to Tehran.
After holding talks yesterday with a senior Iranian security official, a UN spokesman said Mr Annan had received assurances that the Iranian government would cooperate with the UN Security Council resolution on Lebanon, which calls for an arms embargo against Hezbollah.
Iran is a key backer of the militant group and is widely suspected to have supplied arms used against Israel.
