Around 700 vessels involved in transporting Russian oil are currently under international sanctions, according to Vladyslav Vlasiuk, the Ukrainian president's sanctions policy commissioner.

Vlasiuk said this in a televised interview while discussing Russia's shadow fleet and the effectiveness of sanctions imposed by other countries, according to an Ukrinform correspondent.

"Globally, approximately 700 Russian vessels – ships that transport Russian oil – are currently under sanctions. Of those, roughly half have stopped such operations," he said.

Vlasiuk explained that for many of the remaining vessels, being placed on sanctions lists creates difficulties in operating anywhere other than Russia, China and India. At the same time, it can increase their risk of becoming subject to another type of sanctions that Ukraine's Defense Forces have successfully imposed.

"Therefore, I would advise no one to continue transporting sanctioned Russian oil – or liquefied gas, for that matter," the commissioner said.