The US on Wednesday urged its allies not to enter into transactions with Russia and warned that it would trigger American sanctions, a day after it was reported that India was planning to purchase multi-billion S-400 missile defense system from Moscow.

Late last month, the Trump administration imposed sanctions under Countering America’s Adversaries Through Sanctions Act or CAATSA, which was signed into law last August, on China for purchasing fighter jets and missile defense system from Russia.

The CAATSA law tries to push back against Russia’s malign activity around the world.

“We urge all of our allies and partners to forgo transactions with Russia that would trigger sanctions under CAATSA,” a State Department Spokesperson told PTI when asked about India’s plan to purchase multi-billion S-400 missile defense system from Russia.

“The Administration has indicated that a focus area for the implementation of CAATSA Section 231 is new or qualitative upgrades in capability, including the S-400 air and missile defense system,” the spokesperson said.

According to a media report, India and Russia will sign a deal for the multi-billion-dollar S-400 surface-to-air missile system this week.

The signing of the deal for Moscow’s most advanced air defence system will be overseen by Russian president Vladimir Putin, who is visiting New Delhi on October 4-5 for the annual India-Russia summit, the report said quoting a top Kremlin official said.

Putin is scheduled to hold the summit with Prime Minister Narendra Modi on October 5.

“The President is trying to develop a relationship and change that, but we’ve not been successful, at least to date,” US Secretary of State Mike Pompeo told NBC news in an interview.

In September, a senior administration official told reporters that purchase of major military system like multi-billion S-400 missile defense system would be considered as a “significant transaction and thus has a potential” for CAATSA sanctions.

The official emphasized that the ultimate target of these sanctions was Russia.

The CAATSA sanctions in this context are not intended to undermine the defence capabilities of any particular country.

“They are instead aimed at imposing costs upon Russia in response to its malign activities,” the official had said.

The sale has irked India’s defence partner Washington, which has wanted to wean India off Russian technology, and a senior Pentagon official said in August that sanctions against India would come under consideration if its purchase goes through.

Earlier last week, Russia had said that India will make a “sovereign decision” on Russian defence purchases.