Turkey's defence ministry said the first parts of the S-400 Russian missile defence systems were delivered to Ankara on Friday. Turkey's acquisition of the Russian system is a source of tension between Turkey and NATO ally United States.

First part of Russian S-400 missile defence system delivered: Turkey

Turkey on Tuesday accused the US of not acting as an ally in its official response to Washington's ultimatum to Ankara to abandon a Russian missile defence system deal.

US response to S-400 missile defence was not in spirit of alliance: Turkey

Training by Turkish pilots on F-35 fighter jets has come to a faster-than-expected halt at a US air base in Arizona, US officials said on Monday, as the United States winds down Ankara's involvement in the program over Turkey's plans to buy a Russian air defence system.

S-400 row: Turkish pilots halt operations at US air base in Arizona

India on Thursday sealed a $3 billion deal with Russia for leasing of a nuclear-powered attack submarine for the Indian Navy for a period of 10 years, military sources said.

Russia to lease nuclear-powered submarine to India in deal worth $3 billion

Ukraine today officially imposed martial law as its tension with Russia continued days after Ukranian ships were seized by the Russian navy in the Sea of Azov. President Vladimir Putin said that border guards "fulfilled their military duty" and protected Russia's border even as Western powers criticised the Russian government's latest move.

Russia has deployed S-400 missiles in Crimea after martial law in Ukraine: Report

For India, getting a presidential waiver from the biting CAATSA sanctions might not be that easy, some American experts believe referring to the changing political dynamics within the administration and President Donald Trump's personal strong views against New Delhi's trade and tariff policies and calling it a "tariff king".

Getting presidential waiver on S-400 might not be easy for India: Experts

S-400 sytem has an estimated range of 400 kilometres with an altitude of 30 kilometres. It also has the capability to intercept the intermediate-range ballistic missile, not just that the Tiumph system can target aircrafts, UAVs, cruise missiles with equal ease engaging 300 targets at a time.

Star Wars: America's THAAD vs Russia's S-400 missile defence system

The freshly concluded 2+2 dialogue between India and US is significant for it happened against the backdrop of the threat of sanctions against governments working with countries, entities and individuals that the US government considers inimical to its interests.

India must sign S-400 deal with Russia 

Military-Technical cooperation between India and Russia was discussed during the informal meeting between Prime Minister Narendra Modi and Russian President Vladimir Putin in Sochi last month, India's Ambassador Pankaj Saran said.

India won't back out of buying S-400s from Russia despite US pressure: India's envoy