NATO member states have condemned Syria for shooting down a Turkish military jet last Friday.
"We consider this act to be unacceptable and condemn it in the strongest terms," said NATO chief Anders Fogh Rasmussen.
He spoke Tuesday at a news conference in Brussels after a meeting of the ambassadors from NATO’s 28 member states. Rasmussen said NATO stands in solidarity with Turkey.
"It is another example of the Syrian authorities disregard for international norms, peace and security and human life," he said.
Turkish officials say the military jet was an unarmed plane on a training mission and was flying above international waters when it was shot down. Damascus says it acted in self-defense after the plane entered Syrian airspace.
The plane crashed into the eastern Mediterranean and its two pilots are still missing.
Tuesday’s meeting came under Article 4 of NATO’s founding treaty. That article says any country may consult fellow member-states if it considers its territorial integrity, political independence, or security to be under threat.
Rasmussen said NATO had not discussed Article 5 of the group’s founding treaty. Article 5 enables the use of force should a member come under attack.
Hopes for restraint
An international security expert at Britain’s University of Nottingham, Wyn Rees, said NATO is keen to demonstrate its support for Turkey.
"It's a very important state within the alliance. So the fact that it has now suffered this loss of an aircraft, it's important for the other NATO members to show solidarity " he said.
Rees said NATO also hopes to restrain Turkey from escalating the situation.
"The NATO members are not looking for a pretext on which to intervene and therefore they do not want one of their members to drag them into such an action."
Rees says he thinks this situation will be dealt with diplomatically. But he says by shooting down Turkey’s plane, Syria has raised new questions about its internal situation.
"For a country to kind of engage in such an act -- such a hostile act -- seems rather stupid frankly. And one wonders just how much control the Assad regime has over parts of the military now. It kind of raises that deeper question, is the military fully under the command of the civilian government?"
Warning from Turkey
Turkish Prime Minister Recep Tayyip Erdogan launched a stinging attack on Syria's rulers Tuesday, warning them of the "wrath of Turkey." Speaking in parliament, he declared Syria to be "a clear and present danger." The prime minister also announced new rules of engagement for the Turkish army.
"Any military element from Syria moving too close to the Turkish border that is deemed a security risk will be seen as a threat and will be a military target," Erdogan said. "I am warning Syria it shouldn't make any mistake and test Turkey."
Analysts warn of the potential for confrontation as Syrian forces increasingly move closer to the Turkish border to curtail the smuggling of arms to the Free Syrian Army rebels.
Until now, the Turkish army has been under strict rules to avoid confrontation with Syrian forces.
During his address, the prime minister emphasized he is not looking for war.
"Turkey knows what it will do very well. We won't fall into the trap of war provocateurs," Erdogan said. "But we are not a country to sit by after the downing of our plane. We will keep our determination."
The Turkish leader said Turkey will give full support until the Syrian people "are relieved of this dictator," referring to Syria's President Bashar al-Assad.
Danger for monitors
The U.N. Security Council received a closed briefing Tuesday from U.N. peacekeeping chief Herve Ladsous. Diplomats say he told the council that the situation in Syria is too dangerous for U.N. monitors to resume their work there.
They say he added that the Syrian government also refuses to allow observers to use satellite telephones, which he called "key tools" to the operation.
The head of the U.N. observer mission in Syria, Major General Robert Mood, suspended operations on June 16 due to safety risks to the 300 observers. The U.N. has said attackers have targeted the observer team several times in recent weeks with gunfire and bombs.
Violence near Damascus
Rights activists reported heavy fighting in Syria between rebels and government forces in several areas Tuesday.
The Britain-based Syrian Observatory for Human Rights said the army used artillery during clashes with rebels in Damascus suburbs that house families of army officers.
The Observatory also reported violence in the cities of Daraa, Homs, Aleppo, and Deir Ezzor, as well as in Hama and Idlib provinces.
The head of the Observatory, Rami Abdelrahman, said the Tuesday clashes and shelling killed 38 people, including 21 government troops, two defectors and 15 civilians and rebels.
Hennessy reported from London. Jones reported from Istanbul. Carla Babb in Washington contributed to this report.