New Delhi: India has been pursuing an independent foreign policy based on national security interest which also applies to its defence acquisition and supplies, Ministry of External Affairs said on Friday, after US warned New Delhi against the purchase of S-400 air defence system from Russia.

"India-US has a comprehensive global strategic partnership. India has a special and privileged partnership with Russia. We pursue an independent foreign policy, this also applies to our defence acquisition and supplies guided by a national security interest," Ministry of External Affairs spokesperson Anurag Srivastava said.

Outgoing US envoy Kenneth Juster said on Tuesday that the Indian government may have to make hard decisions regarding its decision to purchase S-400 air defence system from Russia.

Speaking at an event here, the diplomat asserted that the US does not want to impose sanctions under Countering America's Adversaries Through Sanctions Act (CAATSA) against "its friends". But he noted that very soon India would have to make choices between "trade-offs" and acquiring modern military hardware from the US.

"The CAATSA sanctions were never designed to harm friends and allies. They were aimed at a particular country. And there are many variables involved in it and I think...I would put that issue to the side because I see other issues that potentially affect the future of the defence relationship," he said.

India signed a USD 5.43-billion deal with Russia for the purchase of five S-400 systems during the 19th India-Russia Annual Bilateral Summit in New Delhi on October 5, 2019, for long-term security needs.

Washington had indicated that the Russian S-400 systems may trigger CAATSA sanctions.

Washington has previously imposed sanctions against China's Equipment Development Department (EDD) for purchasing Russian Sukhoi Su-35 fighter jets and the same S-400 missiles that India is purchasing, triggering a diplomatic confrontation between China and the US.

Turkey, a NATO ally, had also upset the US with its purchase of S-400 missiles in 2018. US President Donald Trump hit back by ending Turkey's involvement in the F-35 programme, though, further sanctions have yet not been imposed.