Mr Obama was speaking after a meeting with Turkish counterpart Tayyip Erdogan in Paris, where he has been attending the climate summit.
“The United States supports Turkey’s right to defend itself and its air space,” President Obama said.
“I want to be very clear: Turkey is a NATO ally.
“We all have a common enemy and that is ISIL and I want to make sure we focus on that threat,” Mr Obama said, using an alternative name for so-called the Islamic State group.
“We discussed how Turkey and Russia can work together to de-escalate tensions” and look to find a diplomatic path to resolve the issue,”