MOSCOW, January 4 (RIA Novosti) – U.S. personnel and equipment has began arriving at Incirlik Air Base in Turkey to support NATO’s Patriot battery deployment in response to alleged security threats from Syria, the U.S. European Command said on Friday.

Some 400 U.S. personnel and equipment will continue to flow into southern Turkey over the next several days by U.S. military airlift, according to the Eucom, based in the southwestern German city of Stuttgart.

“Additional equipment will be moved by sea, arriving later this month,” the Eucom statement said.

Six Patriot battery units, including two each from Germany and the Netherlands, are scheduled to be installed in Turkey by the end of this month.

NATO approved the Patriot batteries deployment last month after a request filed by Turkey. Russia has repeatedly protested the deployment warning that it would mean the direct involvement of NATO forces in the Syrian conflict, further undermining the already unstable situation in the region.

Turkey maintains that it needs the batteries to shore up security on its 900-kilometer (560 mile) border with Syria. Damascus is believed to have several hundred surface-to-surface missiles capable of carrying chemical warheads.

The duration of the deployment will be determined by the contributing nations in coordination with Turkey and NATO, the Eucom said.

Tensions between Turkey and Syria flared dangerously this summer after Damascus shot down a Turkish fighter that had violated its airspace. Turkey threatened retaliation if there was any repeat of the incident, although it admitted the plane had mistakenly strayed slightly into Syria.