More than 14,000 people have been killed in the last 15 months. Despite global outrage over the crackdown by the Assad regime, the international response has been focused entirely on diplomacy and sanctions, not intervention, as the violence escalates.

In a speech to parliament, Turkish Prime Minister Recep Tayyip Erdogan said Syria shot down the unarmed reconnaissance plane in international airspace without warning in a "deliberate" and "hostile" act.

"Any military element that approaches the Turkish border from Syria and poses a security risk and danger will be regarded as a threat and treated as a military target," Erdogan said.

He said border violations in the region were not uncommon and Syrian helicopters had violated Turkish airspace five times recently without a Turkish response. The two countries share a 566-mile (910-kilometer) frontier.

Turkey's limited response to Friday's incident suggested there was no appetite for a violent retaliation. Still, Erdogan cautioned Syria against testing his resolve.