Poland has requested the European Commission's help in keeping Russia from blocking Polish shipments of goods through Russian territory.
The Polish Infrastructure and Transport Ministry on Wednesday said Russia was blocking some of its export shipments to Kazakhstan and Mongolia, as well as to other countries.
Russia banned most fruit and vegetable imports from Poland last month and extended the ban this month to the rest of the European Union in retaliation for Western sanctions over its role in the Ukraine crisis.
Some EU goods are still making it into Russia. They are being re-exported by Belarus and other members of the free trade Customs Union of which Russia is a member.