NATO ambassadors were set to hold emergency talks on Wednesday night after Turkey - a member of the military alliance - fired at targets in Syria in reaction to a shelling, diplomats said, DPA reported.
They said the discussion would take place under Article 4, which allows for consultations if a NATO member state feels its sovereignty is threatened.
Turkey invoked Article 4 once before, when Syria shot down a Turkish warplane in June. But it has so far refrained from calling on Article 5, which would commit NATO to intervene.