NATO foreign ministers have agreed to send Patriot missiles to Turkey to defend the country against possible attack from its neighbour Syria.
The alliance also echoed the United States in voicing grave concerns that the Damascus regime might use chemical weapons, saying doing so would prompt an immediate international response.
The Patriot anti-missile batteries will come from the US, Germany and the Netherlands, but it will be some weeks before they are in place.
NATO denied that the deployment would escalate the conflict.
Secretary-General Anders Fogh Rasmussen said: "I want this to be absolutely clear, this deployment will be defensive only, it will in no way support a no fly zone or any offensive operation."
Turkey, which is a NATO member, has had to scramble its warplanes countless times in recent weeks, as the civil war spilled over the border. The Turkish foreign ministry welcomed the Patriot missile agreement.
