BRUSSELS (AP) — With a deadline closing in quickly, the European Union's chief negotiator in trade talks with Britain said that talks between both sides on even a rudimentary deal still faced too many challenges to yield a result anytime soon.

“At this stage, there are still too many difficulties remaining on important topics," EU negotiator Michel Barnier said as he was on his way to brief the envoys of the 27 member states on Wednesday.

His comments threw a dampener on optimistic reports that progress was being made at a rapid pace on issues such as fisheries rights, one of three remaining major topics that need a compromise solution if a deal is to be found before Jan. 1, when a transition period in the Brexit divorce proceedings ends.

Barnier insisted though that the bloc wasn't ready to give up.

“We are working intensively and will continue working to find solutions," he said.

The lack of progress on fisheries and on the need to have common regulatory standards and fair competition to make sure Britain won't undercut EU businesses has befuddled the negotiating teams for months, as both sides have been trying to strike a trade deal since the U.K. left the EU on Jan. 31.

They must do so within weeks if an agreement is to be ratified by the end of the year, when a post-Brexit transition period ends.

The EU is also fighting Britain's proposed Internal Market Bill, which would be in breach of the withdrawal agreement that underpinned the UK departure conditions.

In the trade negotiations, Britain wants to retain as many of the advantages of EU membership as possible without have to live by the bloc’s rules. The EU is insisting on stringent trade regulations to avoid having a giant buccaneering trade partner on its doorstep that could freely undercut the bloc’s state aid, social and environmental standards.

Hundreds of thousands of jobs are at stake on both sides, especially in nations close to Britain such as Ireland, France, Belgium and the Netherlands.

After negotiating in Brussels this week, the talks are set to move to London again in the coming days.