The anti-missile system used to defend Israel and Saudi Arabia during the 1991 Gulf War is headed to Turkey.
NATO has decided to deploy Patriot anti-missile systems to help protect cities in southern Turkey.
As a member of NATO, Turkey requested the Patriots to bolster its defenses against strikes from the Syrian military.
NATO Secretary General Anders Fogh Rasmussen told reporters on Tuesday the alliance stands with Turkey in "strong solidarity."
"We stand with Turkey in the spirit of strong solidarity," Rasmussen said. "To anyone who would want to attack Turkey, we say, 'Don't even think about it!'"
Rasmussen said the deployment was not a first step toward establishing a no-fly zone nor should it be construed as an offensive operation against Syria.
According to NATO officials, the Patriot batteries will be programmed only to intercept Syrian weapons that enter Turkish airspace. Neither NATO nor the U.S. wants to be drawn into Syria's civil war.