Three cargo aircraft carrying components of Russian S-400 missile defense systems arrived in the Turkish capital Ankara on Friday, said Turkey's national defense minister.
"Three planes were planned for today. As planned, all the aircraft arrived and all activities planned for today have been completed. This process will continue in the coming days," Hulusi Akar told reporters.
Stressing the threats facing Turkey, Akar pointed to the country's longstanding efforts to acquire long-range air and missile defense systems.
"There are some principles that we have set in this regard. In line with these principles, we have had negotiations with China, Russia, the U.S., and France. These negotiations showed us that Russia is the most compatible country," Akar said.
Telling how the contract to purchase the S-400s from Russia was signed in April 2017, Akar said three aircraft had carried components of the systems to Murted Air Base in Ankara.
"The training of our personnel for installing and operating [the Russian S-400s] has been ongoing in both Turkey and Russia," said Akar, adding that the process would continue in the coming days.
Possible procurement of U.S. Patriot missiles is also being evaluated by Turkish officials and institutions, Akar said.
The 2017 contract with Russia followed lengthy efforts to purchase an air defense system from the U.S. with no success.
In recent months U.S. officials have urged Turkey to buy U.S. Patriot missiles, arguing the Russian system would be incompatible with NATO systems and expose U.S. F-35 fighter jets to possible Russian subterfuge.
Turkey, however, emphasized the S-400 would not be integrated into NATO systems and would not pose a threat to the alliance.
Turkey has urged formation of a commission to clarify any technical issues, but the U.S. has failed to respond to this proposal.
The U.S. has also threatened sanctions over the S-400 purchase, with Turkey responding that any sanctions would be met in kind.