He also said that President Aleksandar Vucic has decided to increase the current force of 1,500 soldiers to 5,000.
According to the news agency AP, it is not entirely clear what the order of highest readiness actually means, because the Serbian forces on the border with Kosovo have already been on alert for some time.
Earlier on Monday, the NATO-led peacekeeping operation, Kfor, said it was investigating a shooting that allegedly took place in the northern parts of Kosovo.
The shooting reportedly occurred in the town of Zubin Potok, where local ethnic Serbs have manned road barricades in recent weeks and the situation has been tense.
Kfor has stated that the shooting took place near one of the peacekeeping patrols and that it is not known who was involved. According to a statement, no one was injured in the shooting and Kfor is now working to investigate what happened.