Russia has kicked off production for a batch of S-400 missile defence systems with India’s name on them, bringing a deal reached in 2018 one step closer to fruition despite fevered protests – as well as threats – from Washington.

“The Almaz-Antey concern has begun manufacturing the S-400 systems for India, and Russia will deliver the S-400s to India within the timeframe stipulated by the contract,” said Russian Industry and Trade Minister Denis Manturov, adding that training centres had already been established in India to prepare operators of the missile system.

In general, all commitments undertaken by the parties, including the payment, are being fulfilled in full.

Since Moscow and New Delhi inked a $5.43 billion contract for five S-400 units in 2018, Washington has made numerous attempts to scuttle the deal, warning India the move could restrict the country’s “interoperability” with American systems, and at times even hinting at economic sanctions.

A senior State Department official told reporters last month that should New Delhi go through with the purchase, “there’s a risk of application of sanctions” under the Countering America’s Adversaries Through Sanctions Act (CAATSA), legislation the US has brandished largely against its own allies in an attempt to deter arms deals with Russia, including NATO member Turkey.

Despite the pressure from abroad, India has remained adamant that it be allowed to pursue its military purchases independently, insisting the decision would not be made by the United States or any other foreign country.

Turkey’s own plans to procure the S-400 have not gone over well in Washington, prompting the US to boot Ankara from its F-35 Joint Strike Fighter program, arguing the system is not “compatible” with the stealth fighter or other NATO defence infrastructure. Like India, however, Turkey has shown no signs of abandoning the multi-billion dollar deal.

Designed to intercept enemy missiles and aircraft, the S-400 is Russia’s most advanced long-range air defence platform available for export.