Germany's defense minister inspected Patriot missile batteries close to the Syria-Turkey border on Saturday and said they delivered a "clear warning" to Damascus that NATO would not tolerate missiles being fired into Turkey.
Thomas de Maiziere and his Dutch counterpart Jeanine Hennis-Plasschaert travelled to the Turkish cities of Adana and Kahramanmaras to inspect the batteries provided by their countries at Turkey's request. German Chancellor Angela Merkel was scheduled to visit the same area on Sunday when she begins a two-day visit to Turkey.
The United States has also sent Patriots, which are capable of shooting down hostile missiles in mid-air.
"Our presence here serves to make sure that Syria doesn't turn its capabilities into action," de Maiziere said, while also saying that the risk of attack was "minimal".
"We can see from here that Syria is using rockets - often several times a day."
Syria is believed to have more than 1,000 rockets with a range of up to 700 km, and around 1,000 tons of chemical weapons material.
Turkey is a staunch supporter of the nearly two-year uprising against President Bashar al-Assad and has harbored both Syrian refugees and rebels. Violence has sometimes spilled over the border.
Tensions increased in recent weeks after NATO said it had detected launches of short-range ballistic missiles inside Syria, several of which have landed close to the Turkish border. Turkey has scrambled war planes along the frontier, fanning fears the war could spread and further destabilize the region.
"The Patriot system is strictly for defense, and placing them on our soil within the NATO framework was to protect our people and our soil against possible attack," said Turkish Defence Minister Ismet Yilmaz, travelling with his Dutch and German counterparts.