Turkey took delivery of the first of five CH-47 helicopters on Aug. 25, part of the second batch of Chinooks it is approved to buy from Boeing [BA].

Turkey is a foreign military sales customer for the CH-47F. The country initially ordered six Chinooks with the final delivery in November 2016, according to a Boeing spokesperson.

Turkey then ordered five more helicopters in late 2016. The delivery on the 25th was the first of that batch, raising Turkey’s fielded Chinook fleet to 7 of a planned 11.

The delivery comes amid U.S. concerns with selling high-end military technology to Turkey, including a possible embargo on exports of the F-35 Joint Strike Fighter. The U.S. Defense Department has been directed by Congress to review all arms transfers to Turkey until the Pentagon delivers an assessment of its relationship to Ankara.

Congress’ final version of the fiscal year 2019 defense policy bill halts sales of the F-35 Joint Strike Fighter to Turkey pending a full review of all defense sales to the country and an assessment of its impending purchase of the Russian-built S-400 missile defense system.

Boeing is currently working under a $4 billion multi-year contract let in June 2013 that included 155 CH-47Fs and options for an additional 60 aircraft. Turkey, Australia and the United Arab Emirates were included in that contract.

Boeing this year signed a third multi-year contract with the Army that should carry Block I production out five years, at which point the company will discontinue the legacy configuration in favor of Block II Chinooks.

That $181 million officially covers only six CH-47F Block I aircraft for the U.S. Army, but comes with options for 150 more aircraft.

The company is hoping to add more international orders to that contract and Turkey theoretically could still increase its Chinook buy. It is purchasing the tandem-rotor heavylift aircraft under a 2009 approval by the State Department for up to 14 Chinooks at an estimated $1.2 billion.