India could soon be faced with the threat of US sanctions following a controversial USD 5 billion (around EUR 4.34 billion) weapons deal with Russia, a move analysts say poses more of a headache for Washington than it does Delhi.

Indian Prime Minister Narendra Modi finalized the deal, which will see India take possession of a high-tech S-400 missile defence system, during a bilateral meeting with Russian President Vladimir Putin in the Indian capital New Delhi on Friday.

The deal could potentially open India up to US sanctions under legislation known as Countering America's Adversaries Through Sanctions Act (CAATSA). The law, signed by President Donald Trump last August, is designed to punish Moscow for its “malign activities.”  

Speaking to CNN, Peter Layton, from Australia's Griffith Asia Institute, said the problem for the US is that if it allows India to purchase the S-400 there is no reason why it should not also allow other countries, such as Turkey to do so too.  

The high-tech system is considered the most effective surface-to-air system in its class, surpassing the capabilities of the ageing US Patriot missile system, according to experts.  

It can engage targets, including manned and unmanned aircraft, cruise missile and ballistic missiles at a range of up to 400 kilometres while remaining beyond the reach of standard radar jamming equipment.  

“The S-400 being so capable and at a relatively affordable price is hard for US arms manufacturers to compete against,” said Layton, who described the missile system as offering superior value-for-money to comparable US options.

(USD 1 = EUR 0.86)