NATO gave the go-ahead on Tuesday for the deployment of Patriot surface-to-air missiles to Turkey to protect it from any spillover of the civil war in neighboring Syria, a NATO official said.

"NATO has agreed to augment Turkey's air-defense capabilities by deploying Patriot missiles to Turkey," a NATO official said.

Russia, Syria and Iran have criticized Turkey's request for the Patriots, which can be used to intercept missiles.

Turkey, which has been highly supportive of Syrian rebels, says that the Patriots would defend it against attacks from Syria, possibly with chemical weapons. NATO leaders have repeatedly said they would provide any assistance Turkey needs. Turkey is a NATO member.

Turkey had requested the Patriots in November in the event that the country would need to intercept airborne attacks along its 900-kilometer (560 mile) border with Syria. Turkey has repeatedly scrambled jets to the border and returned shelling when Syrian fire landed on the wrong side of the line.

Watch video 01:26 NATO approves missiles for Turkey

Final approval for the deployment now has to come from Germany, the Netherlands and the United States - the three countries with available Patriot systems. Technical details, such as the number of missiles and their locations, still have to be worked out.

German Foreign Minister Guido Westerwelle said he expected "a broad parliamentary backing" for the move back home, while Dutch Foreign Minister Frans Timmermans said he felt his country has "an obligation as a NATO ally to help protect NATO's borders."

Chemical weapon warnings

The announcement comes amid increasing fears that Syria's government may resort to using chemical weapons to stem a stream of rebel successes. "I am not going to telegraph any specifics what we would do in the event of credible evidence that the Assad regime has resorted to using chemical weapons against their own people, but suffice to say, we are certainly planning to take action if that eventuality were to occur," US Secretary of State Hillary Clinton said on Monday.

US President Barack Obama also added harsh words for the Syrian government. "The world is watching," he said in remarks to a gathering of nuclear proliferation experts on Monday. "The use of chemical weapons is and would be totally unacceptable, and, if you make the tragic mistake of using these weapons, there will be consequences and you will be held accountable."

The Syrian government said on Monday that it would not use chemical weapons against its own people, also appearing to dispute the existence of such weapons in its arsenal.

Toll rises

Early Tuesday, government forces shelled areas near Damascus in response to rebel gains, the Syrian Observatory for Human Rights said. According to the London-based activist group, four rebels and 11 troops were killed in the fighting.

As the situation worsens, the UN announced that up to 25 of about 100 international staff could leave this week and called for more armored vehicles after attacks on humanitarian aid convoys. Two UN convoys en route to Damascus airport were hit by gunfire last week.

Meanwhile, Syrian Foreign Ministry spokesman Jihad Makdissi defected from President Bashar Assad's government and left the country, a regional diplomatic source said on Monday. The news was also reported by the Syrian Observatory for Human Rights.

The Syrian conflict began last March. Activists say more than 41,000 people have been killed.

mkg, hc/msh (AFP, Reuters, dpa, AP)