The Turkish Defense Ministry said that the quadrilateral meeting with Russia, Syria and Iran in Moscow discussed concrete steps that can be taken to normalize Ankara-Damascus relations. The meeting also dealt with ways to intensify efforts to return Syrian refugees to their lands and ways to combat all terrorist organizations and extremist groups on Syrian territory.Relations between Ankara and Damascus have been largely strained since the outbreak of the Syrian revolution in 2011, which later turned into a bloody armed conflict that killed hundreds of thousands and displaced millions.