Fresh Iran nuclear talks agreed with world powers - EU
Six major world powers and Iran are to hold fresh talks on Tehran's nuclear programme, the EU has said.
EU foreign policy head Catherine Ashton said she had replied to a letter from Iran on behalf of the five permanent UN Security Council members plus Germany.
Iranian negotiator Saeed Jalili sent the letter last month proposing talks. No date or venue has been set.
The move comes amid fresh speculation of a pre-emptive military strike against Iran's nuclear facilities.
Iran insists there is no military element to its programme but Western powers fear it is constructing nuclear weapons.
US President Barack Obama told a news conference in Washington DC that he believed there was still a "window of opportunity" to use diplomacy to resolve the standoff with Tehran.
He said there was no need to make a choice in the next fews weeks or months on whether to use military means to stop Iran building nuclear weapons.Parchin access
The statement from Baroness Ashton said the EU hoped that Iran would "now enter into a sustained process of constructive dialogue which will deliver real progress in resolving the international community's long-standing concerns on its nuclear programme."
It added: "Our overall goal remains a comprehensive negotiated, long-term solution which restores international confidence in the exclusively peaceful nature of Iran's nuclear programme."
Since 2003, Iran has held intermittent talks about its nuclear programme with foreign powers. To begin with, France, Germany, and the UK (or the E3) negotiated on their own. In June 2006 the remaining permanent members of the UN Security Council - the US, China and Russia - joined the group (now known as either the E3+3 or P5+1.)
Previous rounds of talks achieved tentative breakthroughs which collapsed soon afterwards. In October 2009, Iran agreed to export more than a tonne of low-enriched uranium in exchange for reactor fuel - a deal that was never implemented.
The most recent rounds of talks - in Geneva in December 2010, and Istanbul in January 2011 - can barely be described as negotiations. They were essentially parallel monologues. Diplomats suggested there was little actual engagement, merely an exchange of prepared speeches. They say that Iran consistently refused to discuss the details of its nuclear programme. The talks broke off.
Over the next year Baroness Ashton exchanged several letters with Saeed Jalili, Iran's chief negotiator. On 14 February, Dr Jalili wrote that Iran was ready for dialogue on what he called a spectrum of issues. Western diplomats say his one, brief reference to the nuclear issue might be a signal Iran is finally willing to engage on the subject.
UK Foreign Secretary William Hague said in a statement that Iran had to "convince the international community that its nuclear programme is exclusively peaceful".
"Until those actions are taken we will not ease the international pressure on Iran."
Iran had earlier said it was prepared under certain conditions to grant inspectors from the UN's International Atomic Energy Agency (IAEA) access to the key military site of Parchin.
The complex, south of Tehran, is dedicated to the research, and the development and production of ammunition, rockets and explosives.
IAEA inspectors wanted to visit last month to clarify the "possible military dimensions" of Iran's nuclear programme, but were denied entry.
But on Monday, Iran's mission to the IAEA said if the UN agency "combined all related issues" then "once more, access would be granted".
Talks between the EU and Iran on the nuclear issue have been off and on for a number of years, with the last round ending in failure in January last year.
Baroness Ashton had written to Mr Jalili last October with an offer of new talks.
In February, Mr Jalili wrote back that Iran was ready for dialogue on what he called a spectrum of issues. He said he welcomed the P5+1's affirmation that it would respect Iran's right to the peaceful use of nuclear energy.
"No doubt that by committing to this approach, our talks for cooperation based on step-by-step principles and reciprocity on Iran's nuclear issues could be commenced," he wrote.
On Monday, Israeli PM Benjamin Netanyahu, on a visit to the US, said time was running out to put a stop to Iran's nuclear programme, warning Israel would "not live in the shadow of annihilation".
He stressed that all options were on the table, but that containment - leaving Iran to develop its programme under monitoring - was "not an option".
On Tuesday, US Defence Secretary Leon Panetta said: "Military action is the last alternative when all else fails. But make no mistake, we will act if we have to."