Nobody can substitute Turkey in the fight against Daesh, said the Bulgarian prime minister on Thursday.
"Geo-strategically, Turkey is located between two continents, fighting against Daesh in the most unstable region of Syria," said Boyko Borissov in a joint news conference with NATO chief Jens Stoltenberg in Brussels.
Stoltenberg said Turkey is important in the fight against terrorism.
"Turkey bordering Iraq and Syria has been extremely important in our fight against Daesh and Turkey hosts 3.6 million Syrian refugees," he added.
"So, when we deal with the migrant or refugee crisis, of course to work with Turkey is essential," the NATO chief said.
Borissov said that Bulgaria does not support sanctions on Turkey over the purchase of the S-400 defense systems from Russia.
"It is not right to put military sanctions on Turkey because Turkey will buy arms from other sources, from Russia," he said.
U.S. lawmakers announced Tuesday they are considering purchasing F-35A fighter jets under Turkish inventory.
This July, Turkey's acquisition of the advanced Russian air-defense system prompted the Trump administration to remove Turkey from the F-35 joint strike fighter program.
The U.S. claims the system could be used by Russia to covertly obtain classified details on the jet and is incompatible with NATO systems.
Turkey, however, counters that the S-400 would not be integrated into NATO systems or pose a threat to the alliance.
Turkish officials have also proposed setting up a commission to study the issue, but have yet to get a positive response from the U.S.
