United Nations: UN Secretary General Ban Ki-moon is worried about Iran's nuclear programme but hopes a stand-off with the international community can be resolved through dialogue, he said in comments published in Italy on Friday.

Asked whether he was concerned about Iran's nuclear programme, he said, "Yes, I'm very worried about Iran's nuclear progress. I hope that, even with the change in negotiators, things can move forward; it is important to continue negotiating with Iran."

The West believes Iran is seeking to build an atomic bomb while Iran says its nuclear programme is for peaceful purposes. Last week it appointed a new negotiator widely seen as taking a tough line in international talks intended to head off an intensification of existing UN sanctions against Iran.

Ban said he had met Iranian President Mahmoud Ahmadinejad briefly during the recent UN General Assembly, and was prepared to meet him privately if necessary.

He said, "I have said with great urgency on many occasions that the differences can be resolved through peace, through dialogue; a war or military action is not desirable in any way."

The United States imposed new sanctions on Iran on Thursday, partly over its nuclear programme, and has refused to rule out military action.