"Constructive" talks: Kamal Kharrazi and Jack Straw
In a meeting with his British counterpart Jack Straw in Tehran, Foreign Minister Kamal Kharrazi said that "handling Afghan issues should be left to the Afghan people".
He is visiting Afghanistan's neighbours in an effort to ensure they support the plan to set up a UN sponsored national unity government.
Upon arrival in the Pakistani capital Islamabad, Mr Straw met with the United Nations deputy representative to Afghanistan, Francesc Vendrell.
Speaking after the meeting, Mr Vendrell warned that some kind of international force might be needed in Afghanistan to maintain security there - highlighting the general distrust between rival factions in Afghanistan.
"It would take a long time to put blue helmets on the ground, but some kind of security force under a United Nations mandate might well be the right approach," Mr Vendrell said.
Complete commitment
Mr Straw described his meeting with Mr Kharrazi in Tehran as "constructive" and welcomed what he called Iran's complete commitment to a broad-based government in Afghanistan.
Mr Straw said that Britain had no interest in keeping troops in Afghanistan longer than necessary.
Britain has currently some 100 special forces at Bagram air base near Kabul.
Last week, the UK put another 6,000 troops on 48-hour stand-by although none of them has been sent amid reports of opposition to the move by the Northern Alliance.
The BBC's diplomatic correspondent, Bridget Kendall, says Mr Straw wants to impress on both Iran and Pakistan the need to work together, if next week's Afghanistan conference in Germany is to have any chance of laying the groundwork for a long-term settlement.
Improved relations
Diplomatic contacts between Iran and Pakistan have improved since September, but relations are still uneasy over Afghanistan.
Iran is favouring parts of the Northern Alliance and is particularly concerned that the voice of Afghanistan's minority Shia Muslims is properly heard.
Pakistan is the former patron of the Taleban and backer of the biggest ethnic group in Afghanistan, the Pashtuns.
The conference, to be held in Bonn, will be the first time rival factions from inside Afghanistan and from émigré groups have agreed to sit down together.
During his visit to Tehran, Mr Straw also held talks with the Northern Alliance's Foreign Minister Dr Abdullah Abdullah, who arrived in the Iranian capital en route to Europe for the talks.
Dr Abdullah said he and Mr Straw discussed their commitment to a broad-based government in Afghanistan, but he refused to endorse the deployment of further foreign troops.
He also repeated that moderate Taleban could not take part in the Bonn meeting: it was a contradiction in terms, he said.
However, the Iranian foreign minister suggested that there might be a role for Afghans who had been working with the Taleban authorities but were not - as he put it - affiliated to the mentality of the Taleban.