The official agreement came as Prime Minister Benjamin Netanyahu ofIsrael, which regards Iran as its most dangerous enemy, was in the midst of a two-day visit to the United States to press his view that diplomatic and economic pressures on Iran to persuade it not to develop a nuclear weapon were not working. President Obama, who has said a nuclear-armed Iran is unacceptable, urged Mr. Netanyahu to give diplomacy and sanctions more time.
The agreement on the talks was made known in a statement from the European Union’s foreign policy chief, Catherine Ashton, acting on behalf of the six powers — the five permanent members of the United Nations Security Council — the United States, Russia, China, France and Britain — and Germany.
Talks about resuming the negotiations have been going on for weeks and Iran’s nuclear negotiator, Saeed Jalili, suggested new discussions in a letter in February as Western powers ratcheted up economic sanctions on Iran’s oil industry and banks. The previous talks broke off in January 2011 in Istanbul.
In a response on Tuesday to Mr. Jalili’s proposal, Ms. Ashton said the European Union hopes that Iran “will now enter into a sustained process of constructive dialogue which will deliver real progress in resolving the international community’s longstanding concerns on its nuclear program.” The timing and location of the talks have not been announced.
“Today I have replied to Dr. Jalili’s letter of February 14,” Ms. Ashton said. “I have offered to resume talks with Iran on the nuclear issue.” Her letter proposed initial talks to build confidence by setting out an agenda on substantive steps.
“Our overall goal remains a comprehensive negotiated, long-term solution which restores international confidence in the exclusively peaceful nature of Iran’s nuclear program, while respecting Iran’s right to the peaceful use of nuclear energy,” the letter said.
Western leaders maintain that the program is designed to give Tehran a nuclear weaponscapability. Iran says the program is for peaceful purposes.
In a separate statement, the British Foreign Secretary William Hague said: “We all agree that the international community should demonstrate its commitment to a diplomatic solution by acknowledging Iran’s agreement to meet, by testing its desire to talk and by offering it the opportunity to respond to our legitimate concerns about its nuclear intentions.”
“It is time for Iran to choose a different path and to show the world that it wants a peaceful, negotiated solution to the nuclear issue. It is for Iran to seize this opportunity and we urge it to do so,” Mr. Hague said. “The onus will be on Iran to convince the international community that its nuclear program is exclusively peaceful, by taking concrete actions.”
The prospect of new talks emerged against a background of mounting tensions, with Iran facing a European oil embargo in July and other sanctions that have deepened its economic gloom. At the same time, Israel signaled increasing readiness to attack Iran’s nuclear facilities to set back the enrichment program, while the United States wants more time for economic sanctions and diplomatic pressure to press Tehran toward a settlement.
At a meeting in the White House on Monday, President Obama urged Mr. Netanyahu to give diplomacy and sanctions a chance to work before resorting to military action. But Mr. Netanyahu said later: “We waited for diplomacy to work; we’ve waited for sanctions to work; none of us can afford to wait much longer.”
There were conflicting reports on Tuesday about Iran’s readiness to permit inspectors from the International Atomic Energy Agency, the United Nations’ nuclear supervisory body, to visit a secret military complex to which they have been denied access. An Iranian news agency, ISNA, said that Iran had reversed its refusal to permit I.A.E.A. inspectors to visit the complex at Parchin, southeast of Tehran.
But a news release from Iran’s representatives at the I.A.E.A. headquarters in Vienna suggested that the offer was conditional, preliminary and limited to only two of the five areas that the agency’s experts wished to investigate. It also accused the agency of ignoring an agreement to postpone its request to visit the secret site at Parchin until after a meeting this week of the agency’s board of governors.
The ISNA report was apparently based on the same news release , which the Iranian mission at the I.A.E.A. said it had issued on Monday.
The I.A.E.A. believes that secret military work may have been carried out at Parchin and has been pressing for access. Last month, a senior delegation from the atomic agency held its second round of talks in a month with Iranian officials in Tehran.
“During both the first and second round of discussions, the agency team requested access to the military site at Parchin. Iran did not grant permission for this visit to take place,” the I.A.E.A. said at the time.
“Intensive efforts were made to reach agreement on a document facilitating the clarification of unresolved issues in connection with Iran’s nuclear program, particularly those relating to possible military dimensions. Unfortunately, agreement was not reached on this document,” its statement said.
But in the news release on Monday offering their own version of the talks in February, the Iranian mission at the I.A.E.A. said Tehran had repeated its readiness to “take practical steps including granting access on two issues” — detonator development and high explosive initiation — but the I.A.E.A. team “did not accept the offer” and returned to Vienna on the instructions of the agency’s director general Yukiya Amano.
Access to the Parchin site may test whether Iran will ever allow the kind of intrusive inspections that most Western officials say are necessary to establish whether Iran has conducted research on nuclear weapons. The last report by the I.A.E.A. in November said Iran had gone beyond theoretical studies about how to detonate a nuclear device, building a large containment vessel at Parchin for testing the feasibility of explosive compression. It called such tests “strong indicators of possible weapon development.”
I.A.E.A. officials offered no immediate response to the Iranian version.
But a Western diplomat familiar with the issue, who spoke in return for anonymity, insisted that Iranian officials had refused to permit the I.A.E.A. team to visit Parchin during the February visit and had instead offered to show the agency’s experts a different site which was not part of their mission.
The conflicting versions of what had transpired seemed to be part of Iran’s negotiating position and an effort by Tehran “not to be seen as unhelpful,” the diplomat said. But, the diplomat said, the agency wanted to pursue the negotiations to gain access to the Parchin site.
At a news conference in Vienna on Monday, Mr. Amano, the agency’s director general, said: “Iran did not provide access to the Parchin site, as we requested.”
“Nevertheless, the Agency will continue to address the Iran nuclear issue through dialogue and in a constructive spirit. The basic objective is to restore international confidence in the exclusively peaceful nature of Iran’s nuclear activities. “
The reported offer to permit access to the Parchin site was the second apparently conciliatory gesture by Tehran in as many days. On Monday, the Supreme Court of Iran overturned the death penalty conviction of a former United States Marine accused of spying and ordered a retrial in a separate court.