London, April 14 (IANS) Key talks involving six major countries and Iran on Tehran's controversial nuclear programme, which resumed Saturday in Istanbul after a 15-month impasse, were described as "positive", even as Iran refused a request from the US for a bilateral meeting.
Known collectively as the P5+1, the six world powers are the US, Britain, France, China, Russia and Germany.
The Iranian delegation was headed by Saeed Jalili, secretary of the Supreme National Security Council, while the six nation delegation was headed by EU foreign policy chief Catherine Ashton.
The West accuses Iran of building nuclear weapons, but Iran maintains that its nuclear programme is for peaceful civilian purposes.
Michael Mann, a spokesman for Ashton, said the talks were "totally different" from the last session 15 months ago.
"There is a positive atmosphere... contrasting with the last time," he was quoted as saying by the BBC.
After a two-and-a-half-hour morning session, Mann said: "The principles for future talks seem to be there."
Russia earlier warned both sides not to "overblow the differences" between them.
"We really need to find a middle course," said Deputy Foreign Minister Sergei Ryabkov. "The negotiations are about renewing confidence."
Meanwhile, Jalili refused a request from the US for a bilateral meeting in Istanbul, Xinhua reported.
Officials said the US delegation participating in the talks was open to a bilateral meeting with their Iranian counterparts.
"The Americans are open to the idea of meeting with the Iranians," a European diplomat participating in the talks told Xinhua.
US President Barack Obama earlier described the P5+1 talks as the "last chance" for diplomacy to work, while Secretary of State Hillary Clinton said Iran had to "demonstrate clearly in the actions they propose that they have truly abandoned any nuclear weapons ambition".
Tehran and the P5+1 have already held two rounds of talks in the past, one in Geneva in December 2010 and another in Istanbul in January 2011.
The second round of the new negotiations will be held in Iraqi capital Baghdad, the date of which will be announced at the end of the Istanbul meeting.
Iranian Foreign Minister Ali Akbar Salehi said in an opinion piece in the Washington Post Friday that Tehran was committed to a peaceful nuclear programme, but it needs to see trust from the international side.
"Despite sanctions, threats of war, assassinations of several of our scientists and other forms of terrorism, we have chosen to remain committed to dialogue," he wrote.
According to CNN, Iran has the right, like other countries -- as a signatory to the Nuclear Nonproliferation Treaty -- to enrich uranium for commercial and research reactors. But the same facilities that are used for peaceful enrichment can be used to enrich uranium for a bomb.
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