Russian President Vladimir Putin and U.S. President Barack Obama talked to each other for more than 30 minutes in an informal meeting on the sidelines of the Group of 20 summit in Turkey on Sunday.
The presidents and two associates could be seen in an intense huddle in a group of chairs around a coffee table on the sidelines of the meeting of international heads of state.
More from NBC News:
'Anonymous' hackers declare war on ISIS in video
Paris bomber entered Europe on migrant boat
150 raids launched as France goes to 'war with terrorism'
"President Obama and President Putin agreed on the need for a Syrian-led and Syrian-owned political transition, which would be proceeded by UN-mediated negotiations between the Syrian opposition and regime as well a ceasefire," a White House official said.
"As the diplomacy continues, President Obama welcomed efforts by all nations to confront the terrorist group (ISIS) and noted the importance of Russia's military efforts in Syria focusing on the group."
The meeting also touched on two other sensitive topics:
"On Ukraine, President Obama reiterated his support for the full implementation of the Minsk agreements, including the withdrawal of heavy weapons, the removal of all foreign fighters, the release of hostages, and the return of the Ukrainian side of the international border to Government of Ukraine control," said the official. "Finally, President Obama offered his deep condolences for the loss of Russian life stemming from last month's MetroJet crash."
Putin and Obama talked "extensively," Russian news agencies cited top Kremlin foreign policy adviser Yuri Ushakov as saying.
"Strategic objectives relating to the fight against the Islamic State are, in principle, very similar, but there are differences on the tactics side," he said.