The US deployment of Patriot missiles in Turkey began Saturday to help the country defend against any possible threats from neighbouring Syria in the throes of a civil war.
"The deployment started early this morning into Incirlik" in southeastern Turkey, Peter Woodmansee, missile defence chief of the US European Command, told AFP on Saturday.
"Several aircraft landed very early this morning with the advance party personnel from 3-2 Air Defense Artillery (ADA) -- the Patriot unit -- arriving as well."
US military personnel and equipment began arriving Friday at Incirlik Air Base to support NATO's Patriot batteries deployment at Ankara's request.
The United States will transport some 400 troops to Turkey in the next several days to operate two Patriot batteries, the Stuttgart, Germany-based U.S. European Command said in a statement on Friday.
Additional equipment will arrive by sea later in January.
The Americans will be based at Gaziantep, 50 kilometers (31 miles) north of the Syrian border.
"The 23 US team members at Gaziantep are determining specific site preparations the US and the government of Turkey must complete before we put the Patriot firing batteries at Gaziantep," said Woodmansee.
"Specifically, living area requirements, logistics, communications, safety and operational aspects of protecting the population in and around Gaziantep in support of the NATO defensive mission."
Germany, The Netherlands and the United States agreed to supply the ground-to-air missile batteries, which Turkey requested after repeated cross-border shelling from Syria, including an October attack that killed five civilians.
The Germans will be based at Kahramanmaras, located about 100 kilometers (60 miles) north of the Syrian border; the Dutch at Adana, about 100 kilometers west of the border.
The Patriot systems are expected to become operational later this month.
Syria's allies Iran and Russia however are opposed to the Patriot deployment, fearing that it could spark regional conflict also drawing in NATO.
"This mission is purely defensive in nature," said Woodmansee.
The Patriots would be deployed "50 kilometres from the border in the vicinity of the town of Gaziantep for the NATO defensive mission to augment Turkey's air defense to de-escalate the situation along the Alliance's border."
Woodmansee said that the deployment of the Patriot systems 50 kilometres from the border would not compromise the effectiveness of the systems.
"Not at all-- the NATO mission is to protect the population. This is why the US, Dutch and German units will deploy near population centres," he said.
NATO-member Turkey, a one-time Damascus ally, has turned into one of its most vocal opponents over the 21-month civil war in Syria that monitors say has killed about 60,000 people.