The EU is preparing to carve out exceptions in its tough sanctions against Moscow that would unblock assets at Russian banks linked to trade in food and fertiliser, a document showed on Tuesday.

Member countries  "want to make it abundantly clear that there is nothing in the sanctions that is slowing the transport of grain out of Russia or Ukraine," an EU diplomat told AFP on condition of anonymity.

The EU's proposal is part of the bloc's latest sanction update that is being negotiated by member states. It will require unanimous approval to enter into force.