"I hope that the rest of Europe will do so well that the British realise at some point that they made a mistake," Schaeuble said at an event in Berlin.

"Whether two years will be sufficient I'm not sure," he added, referring to the deadline for Britain's exit.

Schaeuble also said that changes to the EU treaty were "practically impossible" in the current environment, meaning that closer integration must be done on an intergovernmental basis.