The UK is heading for a Halloween Brexit after the remaining 27 EU nations offered Theresa May a further six months to get her withdrawal deal approved.
The second extension to the Brexit process - initially intended to conclude on March 29 - definitively stopped the clock on a no-deal withdrawal on Friday with less than 48 hours to go.
In an early-hours press conference, European Council president Donald Tusk did not rule out further extensions beyond October.
Speaking in Brussels, he said: "This extension is as flexible as I expected, and a little bit shorter than I expected, but it's still enough to find the best possible solution.
"Please do not waste this time."
Addressing the press shortly before 2am, Mrs May said that she still wanted the UK to leave the EU "as soon as possible".
If a withdrawal deal could be ratified within the first three weeks of May, the UK could still avoid participation in that month's European Parliament elections and leave the EU in June, she said.
Acknowledging "huge frustration" among voters that the UK has not yet left the EU, she said: "The choices we now face are stark and the timetable is clear.
"So we must now press on at pace with our efforts to reach a consensus on a deal that is in the national interest."
Talks between the government and Labour to find a compromise way forward will continue at official level on Thursday.
"I do not pretend the next few weeks will be easy or that there is a simple way to break the deadlock in Parliament," said Mrs May.
"But we have a duty as politicians to find a way to fulfil the democratic decision of the referendum, deliver Brexit and move our country forward. Nothing is more pressing or more vital."
Under the terms of the agreement, the UK can leave at any time if the Withdrawal Agreement reached last November is ratified by the Houses of Parliament.
If the UK fails to take part in elections to the European Parliament on May 23-26, it will automatically leave without a deal on June 1.