Turkey has said it had no intention of going to war with anyone after one of its jets was shot down by Syria last week.
It said it would only act in accordance with international law.
Deputy Prime Minister Bulent Arinc said: "Whatever is needed to be done will definitely be done within the framework of international law.
"We have no intention of going to war with anyone. We have no such intent."
He was speaking at a news conference in Turkey after a seven-hour cabinet meeting on the incident.
Turkey says the aircraft was fired on over international waters, not inside Syrian airspace as Syria maintains.
Syria was later accused of also firing upon a Turkish search and rescue aircraft.
It is urging ministers to honour the collective defence rights of a fellow NATO member.
French Foreign Minister Laurent Fabius called the incident "unacceptable".
"This plane was not carrying arms and was on a routine flight ... there was no prior warning," he said. "This is completely unacceptable."
In Damascus, foreign ministry spokesman Jihad al-Makdissi insisted at a news conference that the plane had been over Syria.
He said: "The Turkish warplane violated Syrian airspace, and in turn Syrian air defences fired back and the plane crashed inside Syrian territorial waters.
"What happened is a gross violation of Syrian sovereignty.
Tomorrow's emergency NATO meeting follows a request from Turkey invoking Article Four of the alliance's founding treaty, covering threats to members' security.
Turkey has already acknowledged that the F-4 might at some point have entered Syrian airspace. But after an initially cautious response, it has toughened its rhetoric.
Foreign Minister Ahmet Davutoglu told Turkey's TRT television that when it was shot down, the aircraft was in international airspace and that Syria gave no warning before opening fire.
The fighter had been on an unarmed training mission, and both crew are still missing.
"Nobody should dare put Turkey's (military) capabilities to the test," Mr Davutoglu said.
UN Security Council member Britain warned that Mr Assad's regime "should not make the mistake of believing that it can act with impunity".
"It will be held to account for its behaviour," Foreign Secretary William Hague said.
US Secretary of State Hillary Clinton condemned a "brazen and unacceptable act" and promised US assistance in the investigation.
Turkish-Syrian relations have been strained by Prime Minister Recep Tayyip Erdogan's outspoken condemnation of the Assad regime's bloody crackdown.
More defections from Syria
Elsewhere, another general has defected from President Bashar al-Assad's regime to join the growing rebel ranks in Turkey, according to media reports.
Turkey's Anatolia news agency said the defection brought to 13 the number of generals seeking refuge in the country since the revolt began nearly 16 months ago.
It said the general, two colonels and 30 soldiers and their families entered Turkey late on Sunday and were taken to Apaydin camp in Hatay province, some 4km from the border.
