Iran has continued disputed nuclear work despite Western calls to halt
An Iranian official has denied he said Tehran was ready for talks with the West on its nuclear programme based on mutual respect and without conditions.
State television had earlier reported that Ali Asghar Soltanieh, Iran's envoy to the UN's nuclear watchdog, had announced its willingness to negotiate.
"There have been no comments or interviews with TV networks on nuclear talks or conditions," he later said.
Iran has been given until September to end its uranium enrichment programme.
Otherwise it faces tougher sanctions. The West suspects Iran is secretly trying to build nuclear weapons, while Tehran insists its programme is solely peaceful.
In a report broadcast earlier on Tuesday, Iranian state television said Mr Soltanieh had "announced Iran's readiness to take part in any negotiations with the West based on mutual respect".
"Talks without preconditions is Iran's main stance in negotiations on the nuclear issue," Tehran's envoy to the International Atomic Energy Agency (IAEA) was quoted as saying.
But the network later reported that Mr Soltanieh was insisting he had not given any interviews or made any comments on the issue.
"Iran's main policies are not changed and that is to pursue its peaceful nuclear activities within the framework of the IAEA," he said.
Mr Soltanieh instead said he had referred to a letter he sent to the IAEA calling for its meeting in September to approve an Iranian initiative to prohibit attacks on nuclear facilities across the globe.
"The only issue that was raised was to ban threats and attacks on the world's nuclear installations, because it is an international issue," he added.
The United States and its ally, Israel, have not ruled out military action to stop Iran's nuclear programme.
Iran's presidential election in June and its turbulent aftermath plunged the country into internal crisis.
Amid deep divisions within the ruling elite and the population, relations with the West were put under further strain and seemed to bode ill for Washington's stated aim of re-engagement with Iran.
Mr Sotanieh's comments came a day before poll-winner Mahmoud Ahmadinejad, an outspoken antagonist of Western powers, was due to submit his cabinet for approval in parliament.
US President Barack Obama said in January that his country was open to dialogue with Iran if its leaders "unclenched their fist". Washington offered talks on trade benefits if Iran stopped enriching uranium.
Tehran has not given a direct response and has continued its expansion of enrichment, which could be harnessed for weapons production in the future.
Iran last held talks with the major powers, the US, China, Russia, France, Germany and the UK, in Geneva in July 2008.
The Obama administration initially set a one-year deadline for reviewing an engagement policy with Iran, but brought it forward to coincide with the G20 summit in late September.
Iran is currently under limited UN sanctions on banking, trade and other activities, as well as travel bans on some individuals involved in the nuclear programme.
The US has not specified what tougher sanctions it might propose.