BRUSSELS, Dec 22 (Reuters) - The European Union is ready to continue negotiations with Britain past the end of the year, two diplomatic sources told Reuters on Tuesday after an update on Brexit by the bloc's negotiator, Michel Barnier.

"Progress has been made. Most issues are preliminarily closed or close to being agreed. However, differences on fisheries remain difficult to bridge," said one EU diplomat. "Unfortunately, the EU is not moving enough yet to clinch a deal on fisheries."

The diplomat, who spoke under condition of anonymity, said EU negotiators were "in a last push" to seal an agreement but added: "The EU will not close its door to the UK and remains ready to negotiate beyond the 1st of January."

Another diplomat said after Barnier's comments behind closed doors: "The negotiations are ongoing, the main problem remains fisheries. Neither side seems to want to stop the negotiation." (Reporting by Gabriela Baczynska; Editing by Susan Fenton)