Turkey has said Syria "clearly and exclusively" bore the responsibility in the downing of a Turkish warplane in the international airspace over the Mediterranean.
"The downing of the Turkish plane without any warning is totally unacceptable and the responsibility of this attack clearly and exclusively lies with Syria," a statement from the Turkish Foreign Ministry said Sunday.
Turkey has said the RF4 warplane was shot down in the international airspace some 13 miles outside of Syria's flight zone.
Turkish Foreign Minister Ahmet Davutoglu said the plane was on a training mission to test Turkey's own national radar system, adding that it was unarmed and had no mission related to Syria.
The statement said Turkey considered the Syrian act "hostile," adding that it constituted "a clear and grave violation" of the international law.
"Turkey reserves all rights stemming from international law and the Turkish government will decisively take all necessary counter measures on over our missing pilots and plane," the statement said of a diplomatic note given to Syria earlier on Sunday.
Turkey has called for an urgent meeting in NATO under Article 4 of the founding treaty of the Alliance to discuss the incident on Tuesday.
US Secretary of State Hillary R. Clinton has condemned "this brazen and unacceptable act in the strongest possible terms."
"It is yet another reflection of the Syrian authorities' callous disregard for international norms, human life, and peace and security," Clinton said Sunday in a written statement.
Turkey said search and rescue team had located the wreckage of the plane 1,300 meters beneath the sea surface, adding that efforts were still underway to find the two missing pilots of the plane.