The European Union on Wednesday said Lithuania had an obligation to allow the passage of sanctioned goods, with the exception of weapons, between Russia and its exclave of Kaliningrad.

While transit by road was not allowed, legal guidance by the EU executive said that "no such prohibition exists for rail transport" from Russia to its outpost of Kaliningrad and that it could not be subject to an outright ban.

Russia has threatened reprisals against the Baltic nation after Vilnius imposed strict restrictions on goods travelling across its territory, arguing it was simply applying EU sanctions.