Belgium and Kharkiv Oblast have similar areas

Belgium covers about 30,689 km², while Kharkiv Oblast covers about 31,415 km². The figures are indeed close: the difference is roughly 726 km², or 2.3% of Kharkiv Oblast’s area. I could not verify the claim that any farthest corner of the region can be reached in 2–3 hours; that depends on the route, roads and travel conditions.