Iran will not discuss the nuclear issue in international talks proposed for later this year, President Mahmoud Ahmadinejad has said.
Last month, Iranian officials agreed to hold talks with a group of six world powers, at the invitation of EU foreign affairs chief Baroness Ashton.
But Mr Ahmadinejad said in a televised speech that Tehran was only prepared to discuss regional security issues, not its "basic right" to nuclear power.
Talks have stalled for over a year.
Iran says its nuclear programme is purely peaceful, but some Western powers fear it is aimed at developing weapons.
'Justice and respect'
The six countries involved in the talks are the five permanent members of the UN Security Council - the US, Russia, China, Britain and France - along with Germany.
EU envoy Baroness Ashton - who has a mandate from the group to negotiate - had proposed talks in November in Vienna, where the UN nuclear watchdog is based.
On Tuesday, Iran said it was ready for talks starting on 23 November or 5 December in Istanbul, Turkey.
Now, a day later, Mr Ahmadinejad has ruled out any discussion of the nuclear issue, though he said Iran was ready to discuss global co-operation on peace and security.
"We have said that the talks be based on justice and respect," he said in a televised speech in the central Iranian city of Qazvin. "That means you [the West] have to climb down from your ivory towers and put aside your arrogance."
Mr Ahmadinejad has previously set out conditions for any nuclear talks, including that the parties publicly declare their positions on Israel's reported nuclear arsenal.
Iran has repeatedly argued that as a member of the Non-Proliferation Treaty (NPT), it has the right to pursue "peaceful nuclear technology" for which it has begun a uranium enrichment drive.
There have been calls from the West for Iran to abandon the sensitive enrichment work, amid accusations it is pursuing a secret nuclear weapons programme.
In June, the UN Security Council adopted the fourth round of sanctions against Iran for its continued defiance.