Russia unilaterally sent about 200 tractor-trailers across the border on Friday, a move characterised by the Kiev government as an invasion.
By Saturday, all of the vehicles had returned to Russia after delivering the goods to the hard-hit rebel stronghold of Luhansk.
The Russian foreign minister, Sergey Lavrov, said on Monday that Russia had notified the Ukrainian government that it was preparing to send a second convoy along the same route in the coming days.
Lavrov also said distribution in Luhansk of the food, water and other goods delivered by the first convoy began on Monday with the participation of the International Committee of the Red Cross.