(File photo)A man looks at a Patriot Advanced Capability (PAC-3) Missile Segment Enhancement (MSE) model by Lockheed Martin at an international military fair in Kielce, Poland September 7, 2017. (Reuters photo)

ANKARA, March 23 (Xinhua) -- Turkey is in talks with the U.S. on purchase of Patriot missile defense systems, Turkish Foreign Ministry spokesperson said Friday.

Speaking at a press conference in Ankara, Hami Aksoy said that Foreign Ministry Undersecretary Umit Yalcin would pay a visit next week to Washington for a face-to-face meeting regarding the missile deal.

Aksoy stressed that Turkey continued to establish a NATO-integrated defense system, adding "our consortium with France and Italy over Eurosam (air defense systems) is being carried out in this framework".

Turkey signed a 2.5 billion U.S. dollars deal with Russia on purchase of the S-400 anti-ballistic defense systems last year amid criticism and doubts from other NATO allies.

Jens Stoltenberg, NATO Secretary-General, described on Feb. 20 Turkey's purchase of Russian S-400 missile systems as "a difficult issue" for the alliance.

Some experts said that Turkey's S-400 deal with Russia would further strain ties between Ankara and Washington and could trigger U.S. sanctions on Turkey.