NATO Secretary General Jens Stoltenberg on Friday  touched upon Turkey-U.S. relations welcoming the recent close contact between the two NATO allies, Stoltenberg said in a news conference following the NATO foreign ministers’ meeting in Brussels, Anadolu reported.

“It was clearly stated during my visit in Ankara that there is now close contact between the United States and Turkey on how to move forward in a way which is as coordinated as possible to avoid any unnecessary problems in northern Syria,” Stoltenberg said referring to his visit to the capital on April 16.

On Turkey’s purchase of the Russian air defense system, S-400, Stoltenberg said: “It is a national decision by any NATO ally to decide what kind of equipment they acquire.

“What matters for NATO is of course the question of whether it's going to be integrated into the NATO air defense system.”

NATO chief said he also discussed with Turkish officials in Ankara about the U.S. statements on possible sanctions against Turkey.