The US President Donald Trump has formally expelled Turkey from the US-led F-35 fighter jet program after Ankara received the Russian S-400s.
The US has been warning Turkey since Ankara insists on its plan of purchasing the S-400s from Russia. The US responded immediately by the ban after Turkey received the Russian missiles.
"Unfortunately, Turkey's decision to purchase Russian S-400 air defense systems renders its continued involvement with the F-35 impossible," White House press secretary Stephanie Grisham said.
"The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities," he added.
On July 12, Turkey's Defense Ministry announced that Turkey received the first shipment of the Russian S-400 missiles. US Secretary of State Mike Pompeo had stated that "The law requires that there be sanctions and I'm confident that we will comply with the law and President Trump will comply with the law."
The Pentagon also ordered Turkish pilots training on the F-35 in the US to leave the country by the end of this month. Turkey had purchased about 100 F-35s and was part of the multinational fighter development programme from its inception more than 25 years ago, reports the Financial Times.