Iranian sources close to the delegation attending the UN General Assembly in New York have confirmed a report by Bloomberg that Iran’s Foreign Minister Mohammad Javad Zarif and US President Barack Obama shook hands. The report, based on anonymous US administration sources due to the sensitivity of the issue, was confirmed Sept. 29 by anonymous Iranian sources.

This is the highest level meeting between the two countries since the 1979 revolution. In 2013, also at the General Assembly, Iranian President Hassan Rouhani and Obama held a historic phone conversation.

According to Islamic Republic News Agency, the meeting between Zarif and Obama was not planned. The source said that the meeting was “incidental,” and that it took place after Rouhani’s speech. As Zarif was exiting the hall, he ran into Obama and Secretary of State John Kerry. The source said they greeted one another and shook hands.

However unlikely the version of the event presented by Iranian sources, it seems likely that they would attempt to downplay the handshake to minimize domestic backlash from conservative foes.