The European Commission has published additional instructions for member states on the transit of goods from Russia. They are not binding, but are advisory in nature.

"Transit of sanctioned goods by road with Russian operators is prohibited under EU measures. There is no such prohibition for rail transport, provided that it does not prejudice member states' obligations to exercise effective control," it says.

In addition, it notes that the transit of sanctioned military and dual-use goods and technologies is completely prohibited in any case - regardless of the mode of transport.

The Commission also stresses the importance of monitoring bilateral trade flows between Russia and the Kaliningrad region to ensure that sub-sanctioned goods cannot enter the EU customs territory.