Turkey says U.S. has not taken step to create S-400 working group

FILE PHOTO: People walk past Russian S-400 missile air defence systems before the military parade to commemorate the 75th anniversary of the battle of Stalingrad in World War Two, in Volgograd

ANKARA (Reuters) - The United States has not moved to create a joint working group to assess its concerns regarding Turkey's purchase of the Russian S-400 missile defense systems, the head of the Turkish Defence Industries Directorate said on Monday.

Speaking to reporters after an event in Ankara, Ismail Demir said Turkish officials were preparing a response to a letter by acting U.S. Defense Secretary Patrick Shanahan, which outlined how Turkey would be pulled out the F-35 fighter jet program if it pressed on with the S-400 deal.

The two NATO allies have sparred publicly for months over Turkey's order for the S-400s, which Washington says poses a threat to the Lockheed Martin Corp F-35 fighters, which Turkey also plans to buy. Turkey proposed the joint working group.

(Reporting by Tuvan Gumrukcu; Editing by Jonathan Spicer)