EU Commission President Ursula von der Leyen has called for post-Brexit trade talks to “intensify” ahead of a call with Boris Johnson on Saturday.
The pair will take part in a video conference to “take stock” of negotiations and “discuss next steps”.
The UK and EU completed the last round of formal talks in Brussels on Friday with a meeting between lead negotiators Lord David Frost and Michel Barnier.
Both sides have said a deal needs to be agreed this month.
The UK’s chief negotiator Lord Frost is to make a statement on the state of the talks later.
UK cabinet minister Robert Jenrick has called on the EU to “show flexibility”.
But president of the European Council, Charles Michel, told reporters the EU had a “clear position” and they were “very calm”.
The meeting between Mr Johnson and Ms von der Leyen will come days after the EU launched legal proceedings against the UK over its plans to override sections of its Brexit divorce deal.
The UK formally left the EU in January, but entered a transition period – where the UK has kept to EU trading rules and remained inside its customs union and single market – to allow the two sides to negotiate a trade deal.
Formal talks began in March and continued through the pandemic, but there has been concerns over whether a plan would be agreed before that period runs out on 31 December.
Issues that have become particular sticking points between negotiators are state aid – when governments give financial support to businesses – and fishing rules.
The BBC’s Europe editor Katya Adler said there had been “rumours of progress” in the talks from UK officials, but they have not been confirmed by EU teams.
Speaking ahead of her call with the UK PM, Mrs von der Leyen said: “We should not forget we have made progress in many many different fields, but of course the most difficult ones are still completely open.”
She pointed to the problems with the so-called “level playing field” with state aid – calling it “a question of fairness” – as well as the issue of fishing,
But, she added: “Overall, where there is a will there is a way, so I think we should intensify the negotiations because it is worth working hard on it.”
The EU has said a deal must be reached before the end of October to allow it to be signed off by the member states before the end of the year, while Mr Johnson has said both sides should “move on” if agreement was not reached by the middle of the month.
If a deal is not done, the UK will go on to trade with the bloc on World Trade Organisation rules.
Mr Jenrick told BBC Radio 4’s Today programme the government was “perfectly content to see the transition period end and us to continue to trade on the same sort of arrangements as Australia” if agreement is not reached.
News of the talks between Boris Johnson and Ursula von der Leyen is significant and Saturday cannot be dismissed as more blah blah in the Brexit process.
Speculation is rife, of course, as to why the prime minister and the EU Commission president have suddenly scheduled their digital tête-à-tête.
In general, it’s interpreted as a positive sign.
The accepted wisdom has always been that negotiating teams can only make so much progress.
And that the final push – the politically tough decisions on how much to compromise on the final sticking points – would have to come from up high.
But we’re not there yet.
It’s possible the prime minister and Mrs von der Leyen are talking tomorrow to explore who is really willing to make what compromises on the final outstanding issues.
For now, the why’s and what’s of Saturday’s talks are pure speculation.
The only thing we know for sure: the UK and EU say they want a deal – though not at any price.
Yet if and when a deal eventually emerges, both sides will have had to make compromises.
There were also concerns trade talks would stall over a new law brought in by the UK government.
MPs passed a new bill last month, which the government said would “protect the integrity of the UK market” and any issues with a border on the island of Ireland in case of a no-deal scenario. The legislation has still to be passed by the Lords.
Ministers conceded some clauses would “break international law” if they were enacted by overriding the deal agreed with the bloc when the UK left in January, known as the withdrawal agreement.
When the government failed to remove the clauses by the end of September, Ms von der Leyen confirmed the EU had sent a “letter of formal notice” to the UK, which could eventually lead to a court case at the European Court of Justice.