Britain's departure from the European Union may still not happen, one of the EU's top officials has suggested.

Donald Tusk, President of the European Council, said the onus was on London to ensure the two sides came to a deal before Britain's scheduled departure from the EU in May 2019. Tusk, updating the European Parliament on Tuesday after a summit of European leaders last week, said it was up to Britain whether there was a "good deal, no deal, or no Brexit" at all.