European Union leaders - in the early morning hours Thursday - agreed to delay Brexit until the end of October, averting a Friday departure from the EU.

That's according to diplomatic sources, after late-night wrangling at an emergency summit in Brussels.

European Council President Donald Tusk announced the breakthrough on Twitter but provided no details, and said he'll meet with UK Prime Minister Theresa May on the agreement.

The decision to extend Friday's deadline appears to be better than May had hoped for, after she made an hour-long pitch for a second extension until June 30.

Now, Britain will not crash out of the bloc on Friday.

And it gives May more time to build a parliamentary majority behind the withdrawal treaty she negotiated with the EU last year.

Leaders agreed to meet again in June to assess the situation.

But Britain could still leave by then if May succeeds in building a coalition for her deal with the Labour opposition - though there is no sign of agreement yet.