Iran will present its own plan at the P5+1 nuclear talks in Geneva next month, Iranian President Hassan Rouhani said at a press conference in New York on Thursday, hours before leaving to return to Tehran.
Earlier on Friday, Iran and the UN nuclear agency held "constructive" talks, signaling hope of finding an end to nearly two years of deadlock over Tehran's atomic program.
It was the first such meeting since Rouhani, a relative moderate who has pledged to try to settle the decade-old nuclear dispute with the West, became Iranian president in early August, succeeding hardliner Mahmoud Ahmadinejad.
The talks in Vienna, home of the International Atomic Energy Agency (IAEA), took place a day after separate but related talks at the United Nations in New York, where Iran and the United States held their highest-level meeting in a generation.
Herman Nackaerts, IAEA deputy director general, said the discussions, at Iran's diplomatic mission, had been "very constructive" but gave no details. At the next meeting on October 28, Iran and the IAEA would "start substantial discussions on the way forward to resolve all outstanding issues," he said.
The IAEA - whose mission it is to prevent the spread of atomic arms in the world - wants to reach a framework deal that would allow it to resume a long-stalled investigation into suspected nuclear weapon research by Tehran, which denies the charge.
For the West, the IAEA-Iran negotiations were a test of any substantive shift by Iran after Ahmadinejad's eight-year tenure when Tehran sharply expanded its nuclear program in defiance of UN demands to curb it.
The meeting - the 11th since early 2012 - was shorter than previous ones, just over four hours.
Iranian Ambassador Reza Najafi, leading the Islamic Republic's negotiating team for the first time since his appointment last month, said he hoped for an agreement soon.
"We, indeed, should continue these constructive discussions and we hope that we could reach an agreement as soon as possible," he told reporters, standing next to Nackaerts.
For several years, the IAEA has been investigating suspicions that Iran may have coordinated efforts to process uranium, test explosives and revamp a ballistic missile cone in a way suitable for a nuclear warhead.
Iran says the allegations are baseless, but has pledged, since Rouhani took office in early August, to expand cooperation with the UN agency. Western diplomats have accused Iran of obstructing the IAEA investigation in the past.
Israel has said Iran's new, conciliatory approach is merely an attempt to "buy time" to push ahead with its nuclear work without fear of military action.
US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif, who met privately in New York as well as in talks with other major powers about the nuclear dispute, both expressed cautious optimism.
Separate from that big power diplomacy to settle the dispute that could yet trigger a Middle East war, the IAEA has held 10 rounds of talks with Iran since early 2012 to try to gain access to its sites, officials and documents for its inquiry.
The two sets of talks represent distinct diplomatic tracks but are linked because both center on suspicions that Iran may be seeking the capability to assemble nuclear bombs behind the facade of a declared civilian atomic energy program.
Iran says its program is a peaceful bid to generate electricity. But its refusal to curb sensitive nuclear work and lack of full openness with IAEA inspectors have drawn tough Western sanctions, hurting its lifeline oil exports.
Rouhani said this week that Iran would never develop nuclear weapons and called for a nuclear deal in three to six months.
Olli Heinonen, a former IAEA chief inspector, and Simon Henderson, of the Washington Institute for Near East Policy, said Iran had "failed to cooperate with the IAEA in resolving questions about whether it has performed design work on an implosion-type atomic bomb."
"This is key to judging the honesty of Tehran's claims that it has never intended to pursue nuclear weapons," they said in an analysis this week.