The state's rural fire service had said it lost contact with the C-130 Hercules aircraft shortly after 2 p.m.
"There appear to be no survivors as a result of the crash down in the Snowy Monaro area," Berejiklian told reporters in Sydney.
"It's impacted heavily with the ground and initial reports are that there was a large fireball associated with the impact of the plane as it hit the ground."