Iran and the United States both have said they were open to a new round of nuclear talks, but their fierce enmity was again revealed by a war of words over the September 11, 2001 terror attacks.
US President Barack Obama and Iranian President Mahmoud Ahmadinejad were both in the spotlight - though they never met - at the UN General Assembly meetings, on a day of dueling rhetoric and diplomatic jockeying.
Ahmadinejad said an Iranian official may meet European Union foreign affairs chief Catherine Ashton next month in a bid to open new international talks on a program which the West says is a quest for nuclear weapons.
He said some of the six powers negotiating on the nuclear dispute - Britain, China, France, Germany, Russia and the United States - had had contacts with Iranian Foreign Minister Manouchehr Mottaki at the UN this week.
Ahmadinejad insisted it was up to Ashton to initiative moves for what he said was a meeting in October scheduled under a longstanding plan.
"If Ms Ashton contacts the Iranian representative she can set a time for talks," the Iranian leader told a press conference.
Denis McDonough, chief of staff of Obama's National Security, noted that Ashton reached out to Iran earlier this year, but never heard back.
"When she hears back, we will know whether they are serious or not," he said.
A day after telling Iran that the door for diplomacy was still open, Obama told the BBC Persian service that a genuine dialogue could see tough new sanctions on Iran removed, along with the fear of armed confrontation.
"Our strong preference is to resolve these issues diplomatically. I think that's in Iran's interest. I think that is in the interest of the international community," Obama said.
"I think it remains possible, but it is going to require a change in mindset inside the Iranian government."
Obama meanwhile lashed out at Ahmadinejad over his tirade to the UN Security Council on Thursday, in which he suggested the US government staged the September 11 attacks in 2001.
"It was offensive, it was hateful," Obama said, slamming Ahmadinejad's remarks, and bemoaning the fact the outburst took place in Manhattan, so close to the Ground Zero footprint of the felled World Trade Center twin towers.