In a dramatic move, US President Barack Obama today spoke to his Iranian counterpart Hassan Rouhani over phone - the first highest-level contact between two countries in more than 30 years - signalling hope of a rapprochement that has potential to transform the West Asia.

In a hurriedly arranged telephone call, Obama called Rouhani who was headed to the airport after spending a hectic week at the New York during which he met a host of world leaders and gave interviews to major US media outlets.

"Just now I spoke on the phone with President Rouhani of the Islamic Republic of Iran. The two of us discussed our ongoing efforts to reach an agreement over Iran's nuclear programme," Obama told reporters at a hurriedly convened press conference.

"I reiterated to President Rouhani what I said in New York. While there will surely be important obstacles to moving forward and success is by no means guaranteed, I believe we can reach a comprehensive solution," he said in his statement to the press at the end of which he did not take any question.

He spoke to the Iranian president soon after his meeting with Prime Minister Manmohan Singh, wherein the latter praised his diplomatic efforts towards Iran and Syria.

Obama said he has directed Secretary of State John Kerry to continue pursuing diplomatic efforts with the Iranian government, a sign that the two countries are serious in repairing their fractured ties after decades of hostilities.

A Twitter account in Rouhani's name later stated, "In regards to nuclear issue, with political will, there is a way to rapidly solve the matter."

It added that Rouhani had told Obama, "We're hopeful about what we will see from" the United States and other major powers "in coming weeks and months."

The conversation between the two leaders came a day after a direct meeting between Kerry and Iranian Foreign Minister Mohammad Javad Zarif, which was described as "constructive" by the Secretary of State.

The two countries have had no diplomatic relations since the 1979 Islamic revolution that overthrew the US-backed Shah regime after massive countrywide protests and led to the seizure of the US Embassy in Tehran.

Obama's call ended on a polite note, according to officials and Rouhani's Twitter account.

"Have a nice day," Rouhani said in English. Obama replied, "Thank you" and then said "Khodahafez", a Persian farewell.