Iran is ready to continue talks with the EU aimed at resolving the stand-off over its nuclear programme, Foreign Minister Kamal Kharrazi has said.
Kharrazi wants assurances that the US will not launch a nuclear strike
His comments come despite apparent deadlock over the issue at a meeting between the sides in London last week.
The US accuses Tehran, which wants to make enriched uranium, of developing nuclear weapons - a claim it denies.
The EU, which opened negotiations with Iran late last year, is calling on Tehran to abandon all such activities.
This, it says, would guarantee that weapons were not being made.
Enriched uranium can be used as fuel for civilian nuclear reactors, but is also the explosive material for atom bombs.
Iran insists its nuclear programme is for civilian use only.
It suspended enrichment activities in November and began talks with Germany, France and the UK.
"We will continue with the negotiations with the European side, provided it will lead us to somewhere tangible in a matter of time," Mr Kharrazi told reporters on Thursday after meeting United Nations Secretary General Kofi Annan.
"But we are determined to continue with our nuclear activities, which are only for producing fuel needed for our power plants."
War of words
On Tuesday, Iran escalated its war of words with the US, calling Washington's arsenal a major threat to global peace.
Mr Kharrazi demanded assurances that the US would not launch a nuclear strike on Iran.
And he rejected a call from President George W Bush for non-nuclear nations to be denied access to nuclear technology.
Mr Kharrazi told a UN conference it was unacceptable for an "exclusive club" of nations to deny nuclear technology to others "under the pretext of non-proliferation".
German Foreign Minister Joschka Fischer has warned that any resumption of nuclear activities by Iran would spell the end of negotiations.
He said restarting the programme could lead to Tehran's referral to the UN Security Council - something for which the US has long lobbied.