Iran should be a part of efforts to resolve the crisis in Syria, United Nations peace envoy Kofi Annan said.

Annan, the former U.N. Secretary-General, made the comments from Tehran, the Iranian capital, where he had been having talks with Ali Akbar Salehi, the Iranian foreign minister. Annan was due in New York on Wednesday for an address to the U.N. Security Council.

Iran and Syria are firm allies, politically and religiously. Both countries are run by Shia Muslims (a minority in the Middle East and, indeed, the world) and enjoy good foreign relations across their common border.

Russia would prefer to have Iran involved as well, but the Iranians have no friends among the rest of the anti-Syria coalition, made up of the United States, several other members of NATO, and a few Persian Gulf states. The question of Iranian involvement is one of several disagreements that have kept Syria from being the sort of anti-dictator target that Libya was in 2011.

Annan is still trying to get both sides of the Syrian conflict to implement his April peace plan. Both sides resumed fighting soon after the initial truce, and the presence of U.N. monitors hasn't stopped the fighting. In fact, the 300 unarmed monitors are now confined to hotels, awaiting the end of their assignments, which is next week.

Syrian President Bashar al-Assad spoke out, proposing to end the conflict step-by-step, concentrating first on the areas affected the worst. Leaders of the main opposition group, the Syrian National Council, based across the border in Turkey, planned to meet with high-ranking Russian officials.

Meanwhile, the fighting goes on, with a human rights organization estimating that the death toll had surpassed 17,000, of which only slightly more than 4,000 were Syrian armed forces.