Iranian leader Hassan Rowhani called Thursday for Israel to put its suspected nuclear arms under international control ahead of a landmark meeting between foreign ministers from Iran and western nations.
Rowhani also said he believed a deal could be made on his country's nuclear drive within three to six months.
The Iranian president spoke at a UN nuclear disarmament conference ahead of a meeting between Iran's Foreign Minister Javad Mohammad Zarif with US Secretary of State John Kerry and ministers from Britain, China, France, Germany and Russia.
The meeting was to discuss western accusations that Iran seeks a nuclear bomb capability. It will also be one of the highest level Iran-US encounters since the 1979 Iranian Revolution.
At the UN conference, Rowhani said Israel should join the Non-Proliferation Treaty which aims to contain the spread of nuclear weapons. Israel has never declared a nuclear bomb but is widely suspected to have several.
Rowhani, speaking as current leader of the Non-Aligned Movement, highlighted the failure of attempts to organize a Middle East nuclear free zone.
"Israel, the only non-party to the Non-Proliferation Treaty in this region, should join thereto without any further delay," Rowhani told the meeting.
He said that "all nuclear activities in the region" would then be subject to International Atomic Energy Agency safeguards.
Iran is in conflict with the UN's atomic watchdog which says it has still not given definitive proof that its nuclear program is for peaceful purposes.
"No nation should possess nuclear weapons, since there are no right hands for these wrong weapons," Rowhani told an audience including UN leader Ban Ki-moon.
Rowhani told the Washington Post he wants a quick accord to end western accusations that Iran is seeking a nuclear bomb.
He said he has the full backing of Iran's Supreme Leader Ayatollah Ali Khamenei to broker a deal.
"The only way forward is for a timeline to be inserted into the negotiations that's short -- and wrap it up," said Rowhani who is attending the UN General Assembly in New York.
"That is a decision of my government -- that short is necessary to settle the nuclear file," he said.
"If it's three months, that would be Iran's choice, if it's six months, that's still good. It's a question of months not years."
Zarif will be the first Iranian minister to sit down with western counterparts to discuss Iran's nuclear program.
And while US officials are saying that no bilateral talks are planned between Kerry and Zarif, there remains the chance for an encounter.
"We're going to have a good meeting I'm sure," Kerry said early Thursday as he met his Chinese counterpart Wang Yi.
The Iranian delegation, however, will only join part of the talks being hosted by EU foreign policy chief Catherine Ashton.
Western diplomats say the meeting will give them a new chance to take the measure of the new Iranian leadership which took office in August.
And they insist it will give the Iranians the opportunity to prove there is some substance behind Rowhani's claims that Iran is only seeking to pursue a peaceful civilian nuclear energy program.
Asked what the Iranians needed to do to prove they are serious, Kerry replied: "I'll let you know after they've been serious."
The international powers made a new proposal to Tehran this year, before Rowhani's election, believed to offer some relief from international sanctions that have crippled Iran's economy in return for a scaling back of its uranium enrichment.
"There's a sense that we never actually got a firm response or a detailed response to that," a senior US official said.
One Western diplomat said, however, that "while we are sensitive to signals there isn't the slightest overture, it's the same old speech."
"If the Iranians say they want a new round of talks as they have something serious to propose, we'll accept. If there is the slightest opportunity, we'll take it."
For his part Zarif said on his Twitter account from New York: "We have a historic opportunity to resolve the nuclear issue," if world powers adjust to the "new Iranian approach."
The United States sought a meeting between President Barack Obama and Rowhani on the sidelines of the UN assembly. But Iran said it was too difficult.
In remarks published Thursday by Iran's official news agency IRNA, Zarif said a meeting between the two presidents "would have been a good beginning."
"A meeting is not an end in itself, nor is it ruled out... President Rowhani has no problem in principle" with meeting Obama, he said.
He called Obama's remarks at the United Nations "more moderate" than in the past, adding: "If that is the basis of a new political will to solve misunderstandings and ease Iranian concerns, this would be more important than a meeting."
Obama and Rowhani both stressed their willingness to try to resolve the nuclear issue.
Rowhani said Iran poses "absolutely no threat to the world," and condemned the international sanctions against his country.
Noting that Rowhani has said Iran will "never" build a nuclear bomb, Obama said there was a basis for "a meaningful agreement."
But he stressed: "To succeed, conciliatory words will have to be matched by actions that are transparent and verifiable" on the nuclear program.