Anti-Brexiteer activist Steve Bray holds placards and an EU-themed umbrella as he stands outside a conference centre in central London on December 4, 2020. (Photo: AFP)

LONDON, Dec. 5 (Xinhua) -- British Prime Minister Boris Johnson and European Commission President Ursula von der Leyen will discuss the post-Brexit trade talks on Saturday afternoon as both sides' chief negotiators paused negotiations over major differences on three core issues.

During their virtual discussions, the two leaders are expected to push both sides closer to gain breakthrough on level playing field, governance and fisheries, which will be vital for a deal to be reached before the Brexit transition period ends on Dec. 31.

Thir phone discussions are seen as an eleventh-hour efforts by London and Brussels to unblock the trade talks between Britain and the European Union (EU).

The two leaders had phone conversations several times instead of face-to-face discussions due to the COVID-19 pandemic.

To bring life back to normal, countries including Germany, China, Russia, and the United States are racing against time to find a vaccine.

"We keep calm, as always, and if there is still a way, we will see," EU chief negotiator Michel Barnier said in London on Saturday as he left for Brussels after an intense week of negotiations.

Chief negotiators from Britain and the EU wrote on twitter on Friday that "the conditions for an agreement are not met, due to significant divergences on level playing field, governance and fisheries."

They agreed to "pause the talks in order to brief their Principals on the state of play of the negotiations."

The negotiations are at a crucial stage as time is running out for both sides to secure a deal before the Brexit transition period expires at the end of the year.

Failure to reach a free trade agreement with the EU means bilateral trade will fall back on World Trade Organization (WTO) rules in 2021.

Britain and the EU resumed face-to-face talks in London last Saturday after an EU negotiator tested positive for coronavirus earlier in November.