Iran's new President Hasan Rouhani waves after swearing in at the parliament in Tehran. (Ebrahim Noroozi/AP)

President Obama confirmed at a White House news conference today that he spoke over the phone with Iranian President Hassan Rouhani this afternoon, the first direct contact between a U.S. and Iranian leader since before the 1979 revolution that has set off three decades of enmity. The call was purely symbolic but would seem to mark a relative high point in U.S.-Iran relations – and the greatest step toward detente in decades.

Rouhani's Twitter account first revealed the call minutes before Obama took the podium, saying they had spoken while the Iranian president was on his way to the airport to fly back to Tehran after a week in New York for the United Nations General Assembly.

According to his Twitter account, Rouhani ended the historic phone conversation by saying "have a nice day." Obama responded with "khoda hafez," colloquial Farsi that communicates a friendly goodbye.

Obama, since before taking office, has stated a desire to speak directly with Iran's leaders and to reach a peaceful compromise on the country's nuclear deal. He sent two letters in 2009 to Supreme Leader Ali Khamenei but was rebuffed. Moderate cleric Hassan Rouhani won the presidency this August, running on a campaign of economic reform and detente with the West.

Obama, in his news conference, said he would seek "transparent, meaningful and verifiable actions" on the Iranian nuclear program. He also reiterated that a larger rapprochement could bring many benefits for the United States. Still, he acknowledged that a mutual U.S.-Iran desire for detente would not be enough.

"A path to a meaningful agreement will be difficult," he said. "And at this point, both sides have significant concerns that will have to be overcome. But I believe we've got a responsibility to pursue diplomacy, and that we have a unique opportunity to make progress with the new leadership in Tehran."