By JOE PARKINSON And STEPHEN FIDLER

ISTANBUL—Turkey on Sunday raised the stakes in a growing crisis over a downed military aircraft, accusing Syria of shooting its jet over international waters on Friday without warning and declaring that it would formally consult with its allies in the North Atlantic Treaty Organization on how to respond.
Speaking some two days after the plane was shot down near the maritime borders of both countries, Turkish Foreign Minister Ahmet Davutoglu told state television that Ankara would react "decisively" and rejected Damascus' statement that it hadn't known the plane had belonged to Turkey.
"Our perspective is that of peace…but nobody can throw Turkey's international security into risk or test Turkey's capacity," Mr. Davutoglu said, adding that while Turkey's response will be "in line with international law," it would be "decisive."
A NATO spokeswoman confirmed that Turkey had called a meeting of envoys to the 28-nation military alliance, scheduled for Tuesday. The consultations were requested under article four of the alliance's founding treaty, which can happen whenever a country deems that its "territorial integrity, political independence or security is threatened," the spokesman said.
Turkey, which diplomats said made the request in a letter received Saturday afternoon at NATO headquarters, is expected to outline its concerns before NATO ambassadors meeting in Brussels on Tuesday. Then, Turkish officials are expected to make a presentation on the downing of the jet.
The incident has inflamed tensions between the neighbors to an ominous new high and added a further serious international dimension to the more than yearlong uprising against President Bashar al-Assad, that Turkey, along with other Western and Arab countries, has supported on the world diplomatic stage.
The last time NATO held article four consultations was also at Turkey's request in early 2003, as tensions were escalating ahead of the expected invasion of Iraq. After that discussion, NATO surveillance and reconnaissance planes were deployed for three months over Turkish airspace.
Diplomats said it wasn't immediately clear what action Turkey would request. They said it was likely that allies would send a signal of solidarity with Ankara, but some played down the likelihood of a significant NATO military response. Some NATO-members weighed in on Sunday to condemn Syria's action.
British Foreign Secretary William Hague denounced the move as "outrageous" and said he would raise the matter with the United Nations. A European Union official said the incident is expected to be discussed during a preplanned discussion on Syria due at Monday's Luxembourg meeting of EU foreign ministers. Meanwhile, Syria's ally Iran on Sunday called for restraint, with Foreign Minister Ali Akbar Salehi calling Mr. Davutoglu to urge both parties to "settle the issue peacefully to maintain regional stability," according to a statement on the Iranian foreign ministry's website.
Speaking two days after the plane was shot down near the maritime borders of both countries, Mr. Davutoglu rejected Damascus' statement that it hadn't known the plane had belonged to Turkey, stressing that the F-4 was clearly marked as Turkish and was unarmed. Syria has said the Turkish aircraft was flying low and well inside Syrian territorial waters when it was shot down.
Mr. Davutoglu said Ankara's formal response would be delivered by Prime Minister Recep Tayyip Erdogan to parliament on Tuesday, after a consultation with opposition leaders and military chiefs.
Turkish television networks reported on Sunday that search teams had located the wreckage of the jet in Syrian waters at a depth of 1,300 meters. Mr. Davutoglu earlier said search and rescue teams were still searching for the two missing pilots, in coordination with the Syrians.
Relations between Turkey and Syria, which share a 565-mile border, started to dissolve last year when Turkish officials began to criticize Mr. Assad for refusing to end the crackdown against domestic opposition to his regime.
In April, when Turkey accused Syrian forces of firing at dissidents inside Turkey, Mr. Erdogan raised the prospect that Turkey could call on NATO to protect Turkey's border against incursions by Syrian forces. The incident didn't prompt NATO military action.
While Ankara has become one of the countries spearheading efforts to force Mr. Assad's ouster, it has been wary of being pressured to lead military action.
Turkish cabinet ministers have openly debated the idea of creating a buffer zone inside Syrian territory after thousands of refugees sought haven on Turkish territory. Turkey now hosts Syria's opposition Syrian National Council in Istanbul, and the leadership of the rebel Free Syrian Army in the southern province of Hatay.
—Ayla Albayrak in Istanbul and Nour Malas in Beirut contributed to this article.Write to Joe Parkinson at [email protected] and Stephen Fidler at [email protected]