United States President Barack Obama has used his speech at the United Nations General Assembly to say the United States wants to reach an agreement on Iran's nuclear programme.
Mr Obama said he was encouraged by the more moderate course of new Iranian President Hassan Rouhani.
He said a diplomatic solution to the dispute must be tried.
"For while the status quo will only deepen Iran's isolation, Iran's genuine commitment to go down a different path will be good for the region and the world and will help the Iranian people meet their extraordinary potential in commerce and culture, in science and education," he said.
He said he had directed US Secretary of State John Kerry to pursue a deal.
However, the White House has quashed speculation Mr Obama and Mr Rouhani will meet during the General Assembly, the BBC reports.
US officials say they offered to have an encounter with Mr Rouhani but the Iranians have an "internal dynamic" they have to manage.
No place for nuclear weapons - Rouhani
In his speech to the General Assembly, Mr Rouhani said his country is prepared to engage in negotiations with the international community over its nuclear programme, provided it is treated equally and with respect.
He stressed Iran was not a threat to the world, rather an anchor of stability, the BBC reports.
Mr Rouhani reiterated Iran's nuclear programme is not aimed at making weapons.
"Nuclear weapons and other weapons of mass destruction have no place in Iran's security and defence doctrine and contradict our fundamental religious and ethical convictions," he said.
Mr Rouhani said sanctions against Iran were "violent".
He also welcomed Syria's acceptance of the Chemical Weapons Convention and condemned the use of such weapons.