Obama Rouhani
U.S. President Barack Obama arrives in the Briefing Room of the White House to deliver remarks on Iran and the federal budget in Washington September 27, 2013. Obama said on Friday he had spoken by phone with Iranian President Hassan Rouhani and both men had directed their teams to work expeditiously toward an agreement on Iran's nuclear program. REUTERS/Kevin Lamarque

A day after Secretary of State John Kerry and Iran’s Foreign Minister Mohammad Javad Zarif held sideline talks at the U.N., the U.S. and Iranian presidents held direct communication over the phone for the first time since 1979, President Barack Obama said Friday.

Obama and his counterpart Hassan Rouhani spoke as Rouhani was returning to Tehran after his four-day visit to the U.N. General Assembly.

"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," Obama said, referring to the controversy over Iran's nuclear program. Iran says it is meant for civilian energy production, but the U.S. and allies including Israel say it is really meant for weapons development -- and that Iran cannot be allowed to have nuclear weapons.

Rouhani's Twitter account announced the historical event before Obama himself did:

Iran's new president, elected in June on a reformist, moderate agenda, may be eager to sit down with the U.S. over its nuclear program because it’s looking to rid itself of sanctions that have crippled the Iranian economy.

Kerry and Zarif's meeting happened on the sidelines of Rouhani's visit to New York for the annual meeting of the U.N. General Assembly. Rouhani has generated considerable buzz with his conciliatory stance, accompanied by calls to make amends with the U.S. and its Western allies -- an approach that is in stark contrast to the antagonistic foreign policy stance of his predecessor, Mahmoud Ahmadinejad.

Talks about a possible nuclear deal will resume on Oct. 15 in Geneva, Reuters reported, after Rouhani called for a deal within three to six months, saying Iran was prepared to accommodate extensive transparency measures to gain the trust of Western nations.

"We have a responsibility to pursue diplomacy and... we have a unique opportunity to make progress with the new leadership in Tehran," Obama said on Friday.