The Russian Federation has once again unilaterally let the fifty-seventh "humanitarian" convoy heading for Donbas cross the border with Ukraine, the press service of the State Border Service of Ukraine said on Thursday morning.

"Since the Russian Federation brought the 'humanitarian aid' in violation of international and national laws and the agreed modalities, and ICRC representatives did not take part in this process, the Ukrainian interdepartmental group has only visually observed [the convoy], without performing control functions," the Ukrainian border agency said.

From 06:08 to 07:05 local time on Thursday, two columns of 46 trucks of the "humanitarian" convoy passed through the Russian checkpoints "Donetsk" and "Matveyev Kurgan" to enter Ukraine's territory, the State Border Service said.

"During the visual inspection of the vehicles, it was established that the trucks were filled with food, medicine, fire-extinguishing equipment. Traditionally, they are half-empty," it said.

The Russian Emergency Situations Ministry in turn reported that the "humanitarian" aid had already arrived at its destination.

"More than 40 trucks carrying over 400 tonnes of humanitarian aid, mostly food and medicines, have arrived in Luhansk and Donetsk. The humanitarian delivery was uneventful," it said.

"As soon as the last vehicle is unloaded, all the trucks will immediately depart for the Rostov region," a ministry representative said.

This is the 57th humanitarian convoy sent to Donbas since August 2014. According to the Russian side, more than 64,000 tonnes of "humanitarian" aid have been sent in the convoys.