Serbia publicly displayed a recently delivered Chinese anti-aircraft missile system, raising concerns in the West and among some of Serbia's neighbors that an arms buildup in the Balkans could threaten fragile peace in the region. (Darko Vojinovic/AP)
HQ-22 anti-aircraft systems are shown during military exercises on Batajnica, a military airport near Belgrade, Serbia, on April 30, 2022. (Darko Vojinovic/AP)
HQ-22 anti-aircraft systems, also known by their export name as FK-3, are shown during military exercises on Batajnica, a military airport near Belgrade, Serbia, on April 30, 2022. (Darko Vojinovic/AP)
A helicopter flies by Serbian Army soldiers participating in military drills April 30, 2022. (Darko Vojinovic/AP)
Serbian Army soldiers perform in recent military drills. Although Serbia officially seeks membership in the European Union, it has been arming itself mostly with Russian and Chinese weapons, including T-72 battle tanks, MiG-29 fighter jets, Mi-35 attack helicopters and drones. (Darko Vojinovic/AP)
Serbian President Aleksandar Vučić reviews am honor guard during a welcome ceremony before April 30, 2022 military exercises. (Darko Vojinovic/AP)
Serbian Army soldiers perform during military drills April 30, 2022. (Darko Vojinovic/AP)