Britain leaving the European Union will take longer than had initially been thought, the president of the European Commission has said.
Speaking in Luxembourg Jean-Claude Juncker said the UK would "have to pay" the Brexit divorce bill before negotiations could move onto the next phase.
The president's comments come after EU negotiators warned that talks on the payments had reached a "disturbing deadlock" this week.
"The British are discovering, as we are, day after day new problems. That's the reason why this process will take longer than initially thought," he said in a speech to students," Mr Juncker said.
"We cannot find for the time being a real compromise as far as the remaining financial commitments of the UK are concerned. As we are not able to do this we will not be able to say in the European Council in October that now we can move to the second phase of negotiations.
"They have to pay, they have to pay, not in an impossible way. I'm not in a revenge mood. I'm not hating the British."
After Theresa May triggered Article 50 in March the UK has two years to negotiate a departure settlement with the EU before it crashes out of the bloc in March 2019.
Negotiations so far have been slower than expected, with hopes that the UK would reach a key milestone by a European Council meeting next week now evaporated.
The EU is insisting that both sides make headway to settling "separation" issues – what will happen to the Northern Ireland border, the divorce bill, and EU citizens living in the UK – before trade talks can take place.
The UK however believes this framework is too strict, and in particular wants to discuss transitional arrangements before these issues are concluded.
On Thursday Michel Barnier, the EU's chief negotiator said he did not believe "sufficient progress" had been made in the three areas to proceed to trade talks. The next possible point "sufficient progress" could be judged is in December, when the next European Council meeting is set to take place.
