VIENNA  - The UN atomic watchdog and Iran hailed Tuesday "productive" and "constructive" talks, in the latest possible sign of Tehran's willingness to ease international concerns about its nuclear work. Iran's envoy to the International Atomic Energy Agency said he presented a new proposal - aimed at clearing up allegations of past nuclear weapons research - that he hopes will "open a new chapter of cooperation". The two sides will meet again in Tehran on November 11, a few days after parallel talks with the P5+1 group of six world powers - the five permanent members of the UN Security Council plus Germany - in Geneva on November 7-8.

The two-day meeting in Vienna was one of a series of gatherings in the Austrian capital this week meant to prepare the groundwork for that Geneva meeting.

"Iran presented a new proposal on practical measures as a constructive contribution to strengthen cooperation and dialogue with a view to future resolution of all outstanding issues," the IAEA's new chief inspector Tero Varjoranta said. No details of the new proposal were given but Varjoranta called the talks "very productive". Iran's envoy Reza Najafi said they were "constructive". The IAEA conducts regular inspections of Iran's nuclear activities but it also wants to probe evidence suggesting that prior to 2003, and possibly since, Iranian scientists conducted experiments aimed at developing a nuclear arsenal.

Iran has consistently denied this, saying the IAEA's claims are based on faulty foreign intelligence from the likes of the CIA and Israel's Mossad that it complains it has not even been allowed to see.

Ten meetings between Iran and the IAEA since a major report from the UN body in November 2011 have failed to make any progress, but Hassan Rouhani's election as Iranian president in August has precipitated a change in tone.

Rouhani has also created optimism for progress in Iran's parallel talks with world powers, which are focused more on Iran's current activities, most notably uranium enrichment.

Iran's Foreign Minister Javad Zarif held a landmark meeting with US Secretary of State John Kerry during the UN General Assembly in September, when US President Barack Obama and Rouhani also shared a historic phone call.

Meanwhile, US President Barack Obama spoke to Prime Minister Benjamin Netanyahu about Iran Monday, a day after the Israeli leader warned Tehran could convert uranium into weapons-grade material within weeks.

The White House said in a short statement that the leaders discussed Iran, Israeli-Palestinian peace efforts and other key issues. Secretary of State John Kerry later stressed diplomacy as the route to test.

Netanyahu warned on Sunday that Iran is capable of converting low-grade uranium to material suitable for use in a weapons program with weeks - even as Washington pursues diplomatic efforts to ease the nuclear showdown.

"The important part stems from technological improvements which allow Iran to enrich uranium from 3.5 percent to 90 percent in a number of weeks," his office quoted him as saying at a cabinet meeting.

Netanyahu is demanding increased pressure on Iran and has expressed skepticism about a diplomatic opening pioneered by new Iranian President Hassan Rouhani which he has called a "charm offensive."