ANKARA  -     NATO Secretary General Jens Stoltenberg said on Monday that he is worried about Turkey’s plans to deploy the Russian S-400 missile defense system despite of US objection.

“The purchase of any equipment is the decision of each NATO ally,” Stoltenberg said in a joint news conference with the Turkish Foreign Minister Mevlut Cavusoglu in the capital Ankara.

“But I am concerned about the potential consequences of the decision to buy S-400. Because the U.S. has made it clear to impose sanctions,” he added. Meanwhile, Stoltenberg welcomed Turkey’s key role in NATO’s training mission in Iraq.

NATO helps protect Turkey with air and missile defense systems and enhanced patrols by Turkey’s Airborne Warning and Control System surveillance planes, he said.