NATO has approved Turkey's request for systems to bolster its defense against Syria.
The news comes after the UN announced it would withdraw nonessential staff owing to the worsening security situation.
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.
Turkey, which has been highly supportive of Syrian rebels, said 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 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.
The United States, Germany and the Netherlands are expected to supply the Patriots. The latter two countries may require parliamentary approval, and it could be a few weeks before NATO deploys the weapons.
NATO Patriot batteries in Germany (Photo: AFP)
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.
NATO voted on the Patriots after talks with Russian Foreign Minister Sergei Lavrov.
The government in Moscow has voted against three proposed UN Security Council resolutions condemning the violence in Syria, saying they were one-sided.
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.