The United States will speed up the delivery of anti-missile defense systems (ABM), which are compatible with NATO standards, to Turkey.

This was stated by Pentagon spokesman Johnny Michael. "We brought our concern to Turkish officials about the potential purchase of the S-400. A NATO-compatible missile defense system remains the best option to protect Turkey from the full range of threats in its region," RIA Novosti quoted him as saying.

He also noted there is "an open dialogue on this issue" and stressed the importance of "maintaining compatibility with NATO in the procurement of any serious defensive systems."

"The US and Turkey have deep and significant relations in the sphere of defense and military trade. Turkey continues to use anti-missile systems with NATO allies, including the United States, for broader, longer-term missile defense needs. The United States is committed to accelerating the delivery of the systems purchased by Turkey as much as possible," Michael added.

He also stressed that Turkey "is a key ally of NATO."

"We are committed to a close partnership in the field of defense," the Pentagon official concluded.

Earlier, Turkish leader Recep Tayyip Erdogan said that Turkey has made the first installment in the framework of the agreement on the delivery of the Russian S-400 anti-aircraft missile systems.

At the end of July, the US Defense Department announced that they are concerned about the incompatibility of the Russian S-400 anti-missile systems that Turkey can buy from Russia.