Turkey has been formally ousted from the US-led F-35 fighter jet programme in response to Ankara’s decision to go ahead and receive the Russian S-400 Triumf missile system.

Washington had warned Turkey that it would no longer be able to remain a partner in the production of F35, a programme in which the Turkish industry has a $12bn stake. Shifting production from Turkey to other suppliers will also cost the US $500-to-600 million.

Turkey has ordered 100 F35s.

In June, the Pentagon wrote to Turkey’s defence minister, Hulusi Akar, detailing the steps Washington would take in the event Ankara went ahead with the Russian order. Turkey is thus giving up a strategic partnership, in which its defence industry would play a key role in the jet-fighter that will replace the F-16 fleet. The Pentagon has already halted Turkey’s pilot training program.

Under the Countering America’s Adversaries Through Sanctions Act (CAATSA) bill, the US has to impose sanctions following significant purchases of a Russian defence system. Turkey’s new system will have to operate alongside British Rapiers, American MIM-23s, Turkish made PMADS and radar systems which are mainly American, British or French. The integration of this system will be a challenge.

During the G20 Summit in Osaka, Japan, President Donald Trump said that he could “wave or delay” sanctions, striking a sympathetic chord with Turkey.

The Russian S-400 system carries a price tag of $2,5bn and comes with the promise of co-production. President Trump accuses the Obama Administration of being responsible for the US failing to anchor Turkey to its Patriot system.