A U.S. State Department official threatened Ankara that Turkey's purchase of Lockheed Martin F-35 Joint Strike Fighter jets would be jeopardized if it does not drop a plan to buy S-400 missile defense systems from Russia.

If it buys the system, Turkey would also be subject to sanctions, according to U.S. Assistant Secretary of State for European and Eurasian Affairs Wess Mitchell, testifying in the Senate.

Since Ankara keeps the two deals separate, finding them critical for its defense needs, this approach makes the U.S. attempts to link the F-35 purchase with the S-400 deal with Moscow an inane move.

Turkish authorities say that the F-35 project is a trade agreement for a U.S.-led project, while the S-400 deal with Russia was inked to strengthen Turkey's air defense systems as a result of lack of support and cooperation from the country's Western allies.