In an interview with German newspaper Die Welt, Jean-Claude Juncker, who leads the EU's executive arm, said an EU army would let the continent "react credibly to threats to peace in a member state or a neighbour of the EU".

The EU is divided on how to deal with an increasingly forthright Russia, which has been accused by Nato and the US of supplying rebel fighters in eastern Ukraine with military equipment and intelligence in the conflict against government-backed forces.

Some member states, including the Baltic countries of Estonia, Latvia and Lithuania, are calling for the bloc to take a much stricter line on its eastern neighbour.

Large member states are also split over the idea of an EU army, with the proposals being cautiously welcomed by many senior German politicians but repeatedly dismissed outright by a succession of British governments.