Turkey's president has said his country will take "necessary" but unspecified action against Syria, a day after Damascus said it had brought down a Turkish military plane that had entered its airspace.
Abdullah Gul said Turkey was still trying to establish the exact circumstances of the incident and whether the jet may have been brought down in Turkish territory.
Turkey's Prime Minister Bulent Arinc has revealed the jet was a reconnaissance plane, not a warplane, according to state television.
– Turkey's president Abdullah Gul
It is not possible to cover over a thing like this, whatever is necessary will be done.
The plane went down in the Mediterranean Sea about eight miles away from the Syrian town of Latakia, Turkey said.
The incident further escalated tensions between the two neighbours, which used to be allies before the Syrian revolt began in March 2011. Turkey has become one of the strongest critics of the Syrian regime's brutal response to the country's uprising.
The incident marks a serious escalation of the Syrian conflict, Iraq's Foreign Minister Hoshiyar Zebari has said.
He told a televised news conference with his Swedish, Bulgarian and Polish counterparts in Baghdad:
The shooting down yesterday of a Turkish aircraft over Syrian territorial waters - this is a serious escalation and indication that the conflict would have far (a) bigger impact than (on) Syria itself.
Turkish media said that Syrian and Turkish coastguards are conducting a joint search mission for the jet's two missing crew members.
The Turkish president added that it was "routine" for jets flying in high-speeds to violate other countries' airspaces for short periods of time.
Today the Turkish Foreign Minister Ahmet Davutoglu held a meeting with commanders from Turkey's military and the head of the intelligence service to discuss what steps Turkey would take in response to the incident.
The meeting lasted two hours and was attended by the military's deputy chief of staff, senior military commanders and the head of the National Intelligence Agency, who also discussed the search operation for the missing pilots.