Britain and the European Union warned each other on Monday that time was running out to reach a Brexit trade deal, with big differences still to be bridged on state aid, enforcement and fishing.
The United Kingdom leaves the EU's orbit on December 31, when a transition period of informal membership ends following its formal departure last January, and the sides are trying to secure a deal to govern nearly $1 trillion in annual trade.
Talks in London over the weekend were "quite difficult" and "massive divergences" remained on elements of fisheries, economic fair play and settling disputes, an EU source said.

European Union's chief Brexit negotiator Michel Barnier wearing a protective face mask is seen in London, UK, November 28, 2020. (Photo: Reuters)

"We are running out of time here," Irish Foreign Minister Simon Coveney said.
Echoing his remarks, German Chancellor Angela Merkel said some EU member states were losing patience.
"We don't need a deal at any price and we have made this clear... A deal is in everyone's interest," she said.
Britain should clarify its positions and "really negotiate" to find a Brexit deal on its future relationship with the European Union, a French presidency official said on Monday.
The French official told Reuters that the EU has made a clear and balanced offer for a future partnership with Britain. "We will not accept a substandard deal which would not respect our own interests," the official added.
A senior EU diplomat said the EU will launch contingency measures on Wednesday or Thursday if it has been unable to reach agreement by then with Britain on a trade deal.
"Companies and institutions like customs offices around the EU need to have clarity about what tariffs to impose and other measures if there is no deal, and by the middle of the week we will have finally reached that point when such measures have to be spelled out," the diplomat said.
"We have been postponing that moment for weeks now, but this is the limit," the diplomat said.

Johnson's spokesman Monday said there had been some progress but "there still remains divergence on issues (such as) fisheries and the level playing field."
"We want to try and reach a free trade agreement as soon as possible but we've been clear we won't change our negotiating position," the spokesman said.
A trade deal would not only safeguard trade but also buttress peace in British-ruled Northern Ireland, though some disruption is almost certain at the busiest EU-UK border points.
Failure to secure a deal would snarl borders, spook financial markets and disrupt delicate supply chains that stretch across Europe and beyond – just as the world grapples with the vast economic cost of the COVID-19 outbreak.

(With input from Reuters)