The German government on Friday called on Britain and France to work to resolve an increasingly bitter row over fishing rights in the wake of Brexit.

A foreign ministry spokeswoman in Berlin told reporters that Germany was following the dispute closely and backed European Commission efforts to "clarify specific issues related to this case".

"From our point of view, what's important now is for both sides to return to the negotiations of the past weeks and months," she said.

London and Paris are at loggerheads over licensing rules for EU boats wanting to operate in waters around Britain and the Channel Islands.

France has been incensed by the rejection of some of its vessels by Britain and the self-governing islands of Jersey and Guernsey, which depend on London for defence and foreign affairs.

French fishermen say Brexit is being used as an excuse to keep many from securing licences for British waters they say they have plied for years.

The spat intensified Thursday when Britain summoned the French ambassador to explain "threats" made over the fishing rights, hours after France's Prime Minister Jean Castex offered to open talks to resolve the disagreement.

An EU spokesman said talks would be held with the UK and France to try to settle the dispute.