European Union flags, seen through Christmas decoration lights, flutter in the wind outside the European Commission headquarters in Brussels, Saturday, Dec. 12, 2020. British Prime Minister Boris Johnson and European Commission President Ursula von der Leyen have set a Sunday deadline to decide whether to keep talking or prepare all-out for a no-deal break. (Photo: AP)

Prime Minister Boris Johnson's Brexit frontman David Frost and EU chief Ursula von der Leyen's chief negotiator Michel Barnier met in a Brussels conference center from early afternoon.

Both sides promised a decision on Sunday as to whether there is still time to close the gap in expectations before Britain leaves the EU single market at the end of the year.

Johnson now says it is "very, very likely" that talks would fail, and on Saturday his government confirmed that patrol boats are on standby to protect British fisheries.

At Thursday's EU summit, von der Leyen told leaders of the 27 member states that the "probability of a no deal is higher than of a deal".

Without a deal, the UK will trade with the bloc on World Trade Organization terms — with all the tariffs and barriers that would bring.