India has placed a US $800 million order for Russian-built S-400 missile defence systems, seemingly ignoring the drama that has engulfed Turkey and its relations with the US following the same decision.

Turkey was kicked out of the F-35 fighter jet program in July after committing to the purchase of the missile defence systems, with the White House saying the nation's "continued involvement with the F-35 [is] impossible", due to the sensitive technological capabilities of the F-35.

"The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities. The United States has been actively working with Turkey to provide air defence solutions to meet its legitimate air defence needs, and this administration has made multiple offers to move Turkey to the front of the line to receive the US Patriot air defence system," a release from the US said five months ago.

"Turkey has been a longstanding and trusted partner and NATO ally for over 65 years, but accepting the S-400 undermines the commitments all NATO allies made to each other to move away from Russian systems. This will have detrimental impacts on Turkish interoperability with the alliance."

During a joint news conference with US President Donald Trump, Turkish President Recep Tayyip Erdogan confirmed that the pair discussed the dispute over the S-400 and F-35, with the Turkish president leaving open the possibility of purchasing a Raytheon-made Patriot missile system, which the US previously offered as an alternative to the S-400.

President Erdogan called a previous US denial of the Patriot systems an “injustice orchestrated against Turkey”, adding: “We have clearly stated to President Trump that under suitable circumstances we can acquire Patriot missiles."

It’s understood that Turkey is now eyeing up purchasing close to a squadron (48 units) of Su-35s, although that figure could indeed double, considering their intention to buy 100 F-35s.

India has no such procurement plans for the F-35, however government officials are keeping a keen eye on the sanctions imposed by the US, through the 2017 Countering America's Adversaries Through Sanctions Act.

The act allows sanctions to be placed by the US on individuals and organisations that engage, or do business with, Russia's intelligence or defence sectors.

With India a key-player in the Indo-Pacific region, an area the US has understandable considerable interest in, the move is likely to draw the ire of President Trump, who has not yet announced the enacting of the mandatory sanctions for Turkey, but that will be done "sooner rather than later", according to White House officials.

India had reportedly been interested somewhat in the purchase of the F-35, however were not yet confirmed international partners of the program and had shown more interest in F-21s and F-18s.

However, they had also committed to the US$3.12 billion purchase of over 400 T-90 main battle tanks, which will be manufactured locally but consist of Russian-built engine and transmission systems.

Historically, India has tried to keep their options open regarding military purchases, without taking Russia or the US's "side".

Currently, it operates Russian, French, UK and locally built combat aircraft in its Air Force, as well as opera.