"There's no meeting of the minds in terms of strategy," he said, which reflected a fundamental difference with President Vladimir Putin over the continuing rule of President Bashar al-Assad.
Speaking at a news conference after meeting with South Korean President Park Geun-hye, Obama said the Syrian civil war was a magnet for extremists and could only end with a political solution leading to a new inclusive government.
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"President Putin believes if he continues to do what he has been doing over the last five years, and that is to prop up the Assad regime, that the problem will be solved."
Obama said he believed in continuing the fight against the Islamic State and other extremist groups, but said the civil war "will only go away if we're able to get a political track and a legitimate inclusive government inside of Syria."
The only understanding with Russia was how to "de-conflict in the event that our planes and their planes might be occupying similar space over Syrian skies," the president said. "We have arrived at an understanding and some channels for communications."
President Barack Obama also said it was essential to get "the Iranians, the Russians, the Turks, the Gulf countries and all the interested parties to sit down and recognize we have to have a political transition if we want to end the humanitarian crisis and save the structure of a unified Syrian state."Drone downed at Syrian border produced in Russia, - Turkish authorities. PHOTO