Germany's Vice Chancellor Gabriel says no new offers for Britain to stay in EU

The European Union will not make Britain any fresh offers to keep it in the bloc and it cannot be "half a partner", German Vice Chancellor Sigmar Gabriel has said.

"The British have now decided to go. We will not hold talks about what the EU can still offer the Britons to keep them in," Gabriel said in excerpts from an interview released on Sunday.

In contrast to conservative Chancellor Angela Merkel, who on Saturday struck a conciliatory tone towards Britain by calling for clear-headed negotiations with the "close partner", Gabriel took a tough stance on the EU's future ties with London.

"It is clear: You can't be a bit pregnant. Nor have half a partnership," he said. Gabriel, a Social Democrat, criticised British Prime Minister David Cameron for "his grand and historic blunder" in calling the referendum that resulted in Britons' 52-48 percent vote to exit the EU, and called for him to go soon.

"Britons will one day curse" Boris Johnson, the leading Brexit campaigner, Gabriel added.

Earlier, Merkel's chief of staff said Britain's politicians should take time to review the consequences of leaving the EU, but he stressed he did not mean they should rethink the Brexit decision itself. "Politicians in London should take the time to reconsider the consequences of the Brexit decision -- but by that I emphatically do not mean Brexit itself," Peter Altmaier told Reuters.