EU chief Brexit negotiator Michel Barnier, wearing a face mask, arrives at St Pancras Station in London on Nov 8, 2020 to attend a new round of talks. (JUSTIN TALLIS / AFP)

LONDON - Britain said on Monday it was open to a "sensible" compromise on fishing and that there was goodwill on both sides to progress towards a Brexit trade deal as a new round of talks began in London.

The United Kingdom left the European Union in January but the sides are trying to clinch a deal that would govern nearly 1 trillion dollars in annual trade before informal membership - known as the transition period - ends on Dec 31.

On fisheries we've always been open to doing a sensible approach, looking potentially at agreements that might span a couple, three years for instance.

George Eustice, British environment secretary

"There are still differences, there are still some obstacles to overcome," British Environment Secretary George Eustice told Sky. "But I think there is now some goodwill on both sides to progress things."

READ MORE: Brexit talks to resume Monday as 'significant differences remain'

Prime Minister Boris Johnson said on Sunday an EU trade deal was "there to be done" and that the broad outlines were clear.

Back in Britain on Monday for another round of talks, EU chief Brexit negotiator Michel Barnier said: "Happy to be back in London today, redoubling our efforts to reach agreement on the future partnership."

Barnier said there remained three keys to unlocking a deal: respectful enforcement mechanisms, guarantees of fair competition, and stable access to markets, including fishing.

Fish

Fishing contributed just 0.03 percent of British economic output in 2019, but many Brexit supporters see it as a symbol of the regained sovereignty they say leaving the EU should bring. Combined with fish and shellfish processing, the sector makes up 0.1 percent of Britain's GDP.

The talks have snagged over state aid rules and fisheries, a sector laden with symbolism for Brexit supporters in Britain.

"On fisheries we've always been open to doing a sensible approach, looking potentially at agreements that might span a couple, three years for instance," Eustice said.

"The issue will become what are the sharing arrangements, how much mutual access do we allow in one another's waters and that's obviously a discussion that will happen annually, but there may also be a partnership agreement that sets out the ground rules as to how we will work on that."

READ MORE: Brexit talks 'fail to agree on fisheries, two other issues’

The prospect of securing a longer term deal with the EU on sharing the fish catch is important for getting a compromise.

Irish Foreign Minister Simon Coveney said on Monday should Biden win the US presidential election, it could have an impact on this week's Brexit negotiations, noting Biden's support for Ireland's position.

However, the European Commission said the question of who is US president would have no bearing on the talks.

Biden, who is proud of his Irish ancestry, has criticized Brexit in the past and said it must not be allowed to harm peace on the island of Ireland. By contrast, US President Donald Trump has spoken out in favor of Brexit.

The upper house of the British parliament, the House of Lords, is due later on Monday to debate Johnson's Internal Market Bill, which would allow Britain to undercut parts of the 2020 Brexit divorce deal and has alarmed the EU.

Eustice said the government would reinstate certain clauses if they were removed from the bill by the House of Lords.