As reported by the "Military Watch" portal, Serbia recently acquired the Russian air defense system S-400 for the Serbian Army!
The S-400 missile battery that was deployed at the Batajnica base near the capital of Serbia, Belgrade, for exercises simulating combat firing on the framework of the "Slovenian Shield" exercise in 2019, was ideal for equipping the air defense units of the Serbian Armed Forces.
Since the Serbian Air Force is considered unlikely to pose a serious threat in any future conflict over Kosovo due to its very small size, its ability to asymmetrically defend its airspace using mobile ground-based air defense systems has become a particularly important issue.
Therefore, it was very significant that Serbia considered the acquisition of the most capable system of the Russian Air Force, the S-400, with speculation about a possible acquisition culminating in the deployment of a battery of the S-400 air defense system in October 2019 in the vicinity of Belgrade.
Shortly after the President of Serbia stated Belgrade's intentions to acquire the S-400 air defense system, the US special representative for the Western Balkans, Matthew Palmer, warned that Washington's response would be sanctions, and since 2017, the US has threatened sanctions against all major Russian arms purchasers within of the American Adversaries Through Sanctions Act (CAATSA).
Apparently in response, Vučić stated on November 6, 2019 that his government has no intention of purchasing long-range air defense systems.