Tehran has repeatedly denied that its nuclear programme is for anything other than peaceful purposes.
But since his June election, Rouhani has made clear he is seeking relief from the sanctions and has welcomed a new start in nuclear negotiations in hopes this could ease the economic pressure.
He has said he has the full support of Iranian Supreme Leader Ayatollah Ali Khamenei, who has the final word on all important matters of state including the nuclear file.
"If there is political will on the other side, which we think there is, we are ready to talk," Rouhani told editors yesterday in New York on the sidelines of the United Nations General Assembly.
"We believe the nuclear issue will be solved by negotiation."
In his debut speech to world leaders at the United Nations on Wednesday, Rouhani repeated Iran's long-standing demand that any nuclear agreement must recognise its right under international treaties to continue enriching uranium.
The US and its allies have long demanded a halt to enrichment, fearing Tehran could secretly build nuclear warheads.
Uranium enriched to low levels can be used as fuel for nuclear energy but at higher levels of enrichment it could be used to build a nuclear weapon.
Rouhani also insisted in his speech that any deal be contingent on all other nations declaring their nuclear programmes too are solely for peaceful purposes, alluding to the US and Israel.
Iran watchers say Rouhani may have limited time to reach a settlement - possibly a year or less - before Khamenei decides negotiations are fruitless. That could explain the urgency in Zarif's call to reach a deal quickly.
"He is not negotiating for the sake of negotiating and dragging it out," Haleh Esfandiari, director of the Mideast programmes at the Wilson Centre think-tank in Washington, said of Rouhani.
"His reputation, and the country's reputation, is at stake. This is an issue they are willing to work on, and move to take concrete steps to serious negotiations."
Rouhani in New York has come across as a more moderate face of the hard-line clerical regime in Tehran.
In particular, he appears to be making an effort to tone down the caustic rhetoric of his predecessor, Mahmoud Ahmadinejad, with regard to Israel - one of the points of friction in relations with the West.
Still his speech to the UN was peppered with Iran's traditional digs at America and the West - a reminder that a diplomatic warming will not come quickly or easily.
Rouhani condemned "the Nazi massacre against Jews, Christians and others" in his remarks to editors yesterday.
"There is no way to ignore Nazi crimes against Jews," he said. But he added "it is important that those victimised not seek compensation by victimising other groups" - a pointed reference to what he has described as Israel's occupation and subjugation of Palestinians.
Israel's UN delegation walked out of Rouhani's speech on Wednesday in protest. But Finance Minister Yair Lapid said Prime Minister Benjamin Netanyahu's instruction to Israeli delegates to walk out was a mistake. He said it created the impression that Israel was not interested in peaceful solutions.
- AP
