The EU's chief Brexit negotiator said Wednesday that a delay of Britain's exit from the bloc is a possibility, but only if London explains in detail what it would do with the extra time.
Any delay would have to be approved by the 27 other EU nations, Michel Barnier told France Info radio.
"And the question they will immediately ask is, What for? That's what will determine the length of any extension," Barnier said.
Their goal would be to ensure that "we don't find ourselves at an impasse as we do today" at the end of any additional period," he said, reiterating that the Brexit date of March 29 "was Britain's choice."
"Speaking objectively, we don't need more time, we need a decision," Barnier said, adding that he remained determined to work towards securing an exit deal.
"It's not correct to say 'no deal' is the most likely scenario. It's possible, but not yet probable," he said.
British Prime Minister Theresa May faces a vote in parliament Wednesday over her newly revised Brexit strategy, which allows for a possible request to delay Britain's EU departure if her divorce deal is not approved.
It was major reversal for May, who had long insisted there would be no delay to Brexit even if that meant crashing out without a withdrawal deal - on citizens' rights, a divorce bill, and the status of the land border with Ireland.
European Council President Donald Tusk had already indicated Monday that European leaders were willing to consider a Brexit delay, calling it a "rational solution" given the political turmoil in Britain.