World powers and Iran still have no date for a new round of talks on Tehran's disputed nuclear drive though it is hoped they could resume next month, diplomats said Friday.
Asked whether the two sides had set a date and venue, a spokesperson for EU foreign policy chief Catherine Ashton said "contacts on when and where the next talks will be held are still taking place."
"We cannot confirm any date,", said Maja Kocijancic. "We are not excluding any location."
"We want to see Iran come back to the negotiating table," she added.
Ashton represents the so-called P5+1 group of powers -- the United States, China, Russia, Britain, France plus Germany -- in talks with Iran on its nuclear program.
Commenting on reports of a possible meeting next week, a European diplomat said on condition of anonymity that "it seems more likely now that the next round will take place in February."
The West was "disappointed there was still no meeting," the source added.
"We showed flexibility when it came to date and venue. We want to present our refreshed offer but didn't get the opportunity to do so."
At the most recent talks, in Moscow last June, Tehran rejected P5+1 calls for it to scale back its uranium enrichment activities, while also asking for relief from sanctions that began to bite in 2012.
Experts fear that Iran is dragging its feet to buy time to develop its nuclear capabilities.
"If Iran would put all the centrifuges they have now installed in Fordo [nuclear site] into operation, their capacity to produce 20 percent-enriched material would be four times as high as it is now," said the diplomat.
Iran refuses to halt uranium enrichment, the most controversial aspect of its nuclear drive, saying it is purely for civilian purposes.
The West accuses Tehran of working towards acquiring atomic weapons under the guise of its civilian nuclear program, a charge Iran vehemently denies.
In Washington on Thursday, Senator John Kerry, the secretary of state designate, said the United States will not be satisfied with containing Iran but will seek to stop it from obtaining a nuclear weapon.
"I repeat here today: our policy is not containment. It is prevention and the clock is ticking on our efforts to secure responsible compliance," he told lawmakers at a Senate hearing to confirm him as the next top US diplomat.
Directing an appeal at Iranian leaders, Kerry urged Tehran to prove that its nuclear program is solely for domestic energy purposes.
"If their program is peaceful, they can prove it, and that's what we're seeking," he said.
Kerry stressed that under his leadership the State Department would remain committed to its dual-track policy towards Iran, which includes talks and tough global sanctions now beginning to bite deep into the Iranian economy.