The main battle tanks manufactured during the Cold War era needs modernization in line with the requirements of the modern battlefield. Serbia, which has a well-established defence industry infrastructure inherited from Yugoslavia, is also working to upgrade platforms in its inventory.

Serbia took over a significant number of M-84 main battle tanks after the dissolution of Yugoslavia. For platforms that have been in use since 1985, Serbian armed forces launched a modernization program. The upgraded vehicle was introduced at an event held at the Čačak Technical Overhaul Institute.

The platforms, called M-84 AS1 after the upgrade process, will be modernized in two stages. In tanks where eight subsystems will be improved in the first phase, 12 subsystems will be subjected to modernization in the second phase. In the first step, the protection level of the platforms against all current threat types will be increased with a non-explosive reactive armour blocks called ERO-19. In addition, vehicles are equipped with various optics and electro-optics for additional protection against wire-guided and laser-guided anti-tank missiles. In this way, the survivability of tanks will be improved. The situational awareness of the crew was also increased. The tank commander is equipped with a 12,7 mm RWS RCWS (remote control weapon system) that can make accurate shots in any weather conditions with the fire control system and thermal imager, as well as the TOMS surveillance system, which provides a 360-degree view. The tanks are also integrated with the integrated DNNS 2ATK day/night sight system and an advanced fire control system. In this way, an increase in the hit-at-first shot rate is expected. The platforms are also equipped with the KIS M-84 combat information and control system, as well as the SOFTKIL jamming system, as well as an engine protection system that prevents the driver from damaging the drive system during the first start of the engine.

Officials from the Serbian Army stated that modernization has been expected since 1991 to double the capabilities of the tank in question.