Signs Russian Troops Departing Chernobyl: Pentagon

Forces are leaving the Chernobyl plant, heading north towards Belarus. The reasons for their departure are not entirely clear, but it is assessed as part of a larger effort to refit and resupply, rather than due to health hazards or emergencies at Chernobyl.

How does the speaker assess the situation regarding the forces at Chernobyl?

What larger effort is mentioned in relation to the forces at Chernobyl?