Moscow: During the India visit of Russian President Vladimir Putin,  a $ 5 billion deal will be signed for the supply of S-400 air defence systems to India, a top Kremlin aide said told media. This is reportedly the first official confirmation of the deal.  “The president is leaving for India on October 4,” Putin’s top foreign policy aide Yury Ushakov told reporters.

“The key feature of this visit will be the signing of the agreement to deliver S-400 air defence systems,” The Times of India reported Ushakov as having said. The value of the contract will be more than $5 billion. Moscow has been negotiating to sell the S-400 long-range surface-to-air missiles to India for months.

The S-400 deal has been caught in a diplomatic crossfire between US and Russia, with the former threatening Delhi and other partners with sanctions if the deals go through.  India had said that it will go ahead with the acquisition of the missiles from Russia despite pressure from the US.  India has signalled it will ask Washington for a special waiver from sanctions, though a US official last week said there is no guarantee it would do so.

The US had imposed sanctions on Russia, particularly for its alleged meddling in the 2016 presidential election, under the Countering America’s Adversaries Through Sanctions Act (CAATSA), a law that mandates the US government to impose sanctions on countries who are engaged in military transactions with Russia. The S-400, which has been in service since 2007 is considered as Russia’s most advanced long-range surface-to-air missile defence system.

Defence Minister Nirmala Sitharaman has insisted the deal will go through despite the sanctions. Referring to CAATSA, she has said it is an American law and not a UN law and India has conveyed its position on the issue to the US. “Our defence relation with Russia has endured several decades and we have conveyed about it to a US Congressional delegation which visited India recently,” she said.