Turkey is expected to take delivery of the first shipment of a $2,5bn Russian S-400 Triumph air defence system, defying US pressure.

Washington is threatening Ankara with sanctions over the acquisition of one of the world’s most advanced air defence systems, capable of taking out drones, fighter jets and cruise missiles.

NATO allies are concerned that the system will jeopardise the stealth capacity of the F-35 stealth fighter jet, as Russian military stationed can collect sensitive data about the fifth-generation aircraft. Turkey insists it can protect the security of the F-35 by ensuring that the air defence system is not linked to the broader Nato-integrated defence architecture.

The Pentagon is expected to suspend Turkey’s purchase of 100 F-35 aircraft, also cancelling a co-production agreement with Turkey. Ankara may also face other economic sanctions under Countering America’s Adversaries Through Sanctions Act (CAATSA).

The threat of sanctions adds to the volatile political climate that follows the firing of the Governor of the Bank of Turkey, Murat Cetinkaya, on Saturday.

President Recep Tayyip Erdogan justified his decision to oust him after a clash over the pace and depth of rate cuts, going on record to claim the right to intervene on monetary policy. “From now on, the central bank will provide stronger support for our economic programme,” Erdogan said on Wednesday, confirming the view that monetary policy is now government policy.