BREXIT negotiations look to have almost stalled although efforts to reach an agreement will continue.
Michel Barnier said "very serious divergencies remain" between the EU and UK negotiators.
The problematic areas are still fishing and state aid.
In an update to MEPs, Mr Barnier said: "Despite EU efforts to find solutions, very serious divergences remain in level playing field, governance and fisheries.
"These are essential conditions for any economic partnership."
Lord Frost said progress had been made during two weeks of intensive talks but "wide divergences remain on some core issues".
"We continue to work to find solutions that fully respect UK sovereignty," he said.
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