NATO says it will consider a request by Turkey to deploy Patriot anti-missile systems to protect its border with Syria, "without delay".
Secretary General Anders Fogh Rasmussen said such a move would "augment Turkey's air defence capabilities" and "contribute to the de-escalation of the crisis along NATO's south-eastern border".
Patriot batteries use radar to locate incoming missiles. Surface-to-air missiles are then launched from giant containers and are guided onto their targets.
The BBC reports Germany has already said the request should be approved.
On several occasions last month, Turkish forces returned fire across the border into Syria after Syrian mortar shells landed inside its territory.
The exchange of fire followed the deaths of five Turkish civilians in Syrian shelling.
Until last year, Turkey and Syria were close allies, but Ankara is now backing the Syrian opposition and calls for the resignation of President Bashar al-Assad.
Turkey has a 900km border with Syria.