NATO's secretary general said Tuesday that Turkey's purchase of a Russian missile defence system represented a "difficult" problem for the alliance, but stopped short of saying Russian President Vladimir Putin was driving a wedge between NATO allies.
"This is a serious and difficult issue for all of us. It is up to Turkey to decide because NATO doesn't have a policy where we can decide exactly what kind of equipment different allies are buying. But at the same time, we are concerned about the consequences," Jens Stoltenberg said in an interview Tuesday with CBC News Network's Power & Politics.
Turkey is a member of the North Atlantic Treaty Organization, a military alliance of 29 countries, including Canada and the U.S., that aims, in part, to prevent Russian encroachment in Europe.
Interoperability with NATO allies lies at the heart of the problem, said Stoltenberg.
"The systems have to be able to work together, to share a radar picture, to operate together. And of course a Russian system S-400 can never be integrated into the integrated NATO air and missile defence system," Stoltenberg told host Vassy Kapelos.
Turkey began receiving components of the Russian missile defence system last week, despite strong opposition from the U.S.
The U.S. reportedly warned Turkey at the end of June that the country would be prohibited from buying high-tech, American-made F-35 stealth fighter jets if it proceeded with the purchase of the Russian missile system.
U.S. President Donald Trump described the situation Tuesday as unfair, appearing to blame decisions made by the former administration for the current situation.
"The Obama administration would not sell them the Patriot missiles. They need the Patriot missiles for defence. They would not sell them under any circumstance," said Trump.
"We are now telling Turkey that because you have really been forced to buy another missile system, we're not going to sell you the F-35 fighter jets. It's a very tough situation that they're in."
Washington is concerned the S-400 missile could compromise Lockheed Martin's F-35 fighter jets.
Stoltenberg said that NATO and the U.S. are working to find a solution that could include the U.S., France and Italy providing Turkey with alternative missile defence systems.
Time is running out, however. Turkish President Recep Tayyip Erdogan said Monday that Turkey will have the Russian missile defence system fully deployed in less than a year.
Erdogan also said Turkey hopes to co-produce high-tech weaponry systems with Russia in the future.
Turkey has had a fraught relationship with the U.S. for years. American support for Kurdish militias in Syria alarmed Ankara and led to seemingly closer ties with Moscow.
With files from the Associated Press.