Updated

The Patriot air defense missiles being deployed to protect Turkey from spillover from Syria's civil war will become operational at the end of January, officials said Thursday. In addition, NATO will send Turkey special aircraft that can detect missile launches from Syria.

A number of Syrian shells have landed in Turkish territory since the conflict in the Arab state began in March 2011. Turkey has condemned the Syrian regime of President Bashar Assad, supported Syrian rebels, and provided shelter to Syrian refugees, and Ankara is particularly worried that Assad may get desperate enough to use chemical weapons.

NATO foreign ministers endorsed on Turkey's request for the Patriots on Nov. 30. The Netherlands, Germany and the United States are the only NATO members that have the advanced PAC-3 model Patriots that Turkey needs to intercept ballistic missiles.

Germany and the Netherlands will each provide two batteries of the U.S.-built air defense systems. The U.S. would likely fill any gaps, possibly by sending some from its stocks in Europe. Up to 400 German and 360 Dutch troops will man the batteries, likely from somewhere well inland in Turkey.

Dutch Prime Minister Mark Rutte said Thursday that the three nations are working closely with Turkey "to ensure that the Patriots are deployed as soon as possible."

"We expect them to be operational by the end of January," Rutte said at a joint press conference after meeting NATO Secretary-General Anders Fogh Rasmussen at the alliance's headquarters. "The location will be decided with our allies, and several matters need to be sorted out before the Patriots can be deployed."

Due to the complexity and size of the Patriot batteries — including their radars, command-and-control centers, communications and support facilities — they cannot be flown quickly by air to Turkey and will have to travel by sea, officials said.

Syria is reported to have an array of artillery rockets, as well as short-range missiles — some capable of carrying chemical warheads. These include Soviet-built SS-21 Scarabs and Scud-B missiles, which were originally designed to deliver nuclear warheads. Both have inertial guidance systems that have proven fairly accurate.

NATO also will deploy its Airborne Warning and Control System aircraft, or AWACS, to Turkey, said an official who spoke on condition of anonymity because alliance rules do not allow him to speak on the record.

The aircraft, which can detect launches of ground-to-ground missiles, are scheduled to participate this month in a training exercise in Turkey, the official said. The planes will exercise command and control procedures as well as test the connectivity of various NATO and Turkish communications and data sharing systems.

Turkey has been a NATO member since the early 1950s. Its air defenses consist mostly of short-range Rapier and Stinger systems, and U.S.-made Hawk low- altitude missiles. Ankara has been looking to acquire a new high-altitude defense system to replace its Cold War-era Nike-Hercules batteries.