The announcement comes just days after Syria allegedly launched Scud missiles from Damascus at rebels in the north. Syria has denied using Scud rockets.
But U.S. officials claimed one of the missiles came close to the Syrian border with Turkey, reported CNN.
The move to send the reinforcements was approved by U.S Defense Secretary Leon Panetta, who is currently en route to Turkey.
The plan calls for two Patriot missile batteries that can hit planes and missiles emanating from Syria, and 400 soldiers to operate them.
Panetta was frank about the possible reaction from Damascus: "We can't spend a lot of time worrying about whether that pisses off Syria," he told CNN.
Germany and the Netherlands are also deploying two Patriot batteries each to the Turkish border to bolster the NATO ally's defenses.
NATO approved the decision last week but admitted the batteries were not enough to cover all potential sites, reported the New York Times.
The batteries are expected to be operational by January.
Many believe that the Syrian regime is facing immense pressure as sanctions and territorial losses take their toll.
Last week, news reports quoted U.S. intelligence officials saying that Syria may be prepping chemical weapons as the regime becomes more desperate. Officials now say the threat has been diminished.