LONDON (AP) — Britain and the European Union warned Tuesday that talks on a post-Brexit free-trade deal are teetering on the brink of collapse, with just over three weeks until an economic rupture that will cause upheaval for businesses on both sides of the English Channel.

Officials downplayed the chances of a breakthrough when Prime Minister Boris Johnson heads to Brussels for face-to-face talks with European Commission President Ursula von der Leyen in the next few days.

With negotiators deadlocked on key issues after months of tense talks, Johnson said “the situation at the moment is very tricky.”

“But hope springs eternal. I will do my best to sort it out if we can," he said.

German European Affairs Minister Michael Roth said "political will in London” was needed to secure a deal.

“Let me be very clear, our future relationship is based on trust and confidence. It’s precisely this confidence that is at stake in our negotiations right now," said Roth, whose country currently holds the EU’s rotating presidency.

"We want to reach a deal, but not at any price,” Roth told reporters before chairing videoconference talks among his EU counterparts.

Johnson and von der Leyen, head of the EU’s executive arm, spoke by phone Monday for the second time in 48 hours but failed to break the trade talks impasse. They said afterwards that “significant differences” remained on three key issues — fishing rights, fair-competition rules and the governance of future disputes — and “the conditions for finalizing an agreement are not there.”

The two leaders said they planned to discuss the remaining differences face to face “in Brussels in the coming days.”

EU chief negotiator Michel Barnier met his U.K. colleague David Frost in Brussels on Tuesday to take stock and “prepare the next steps,” Barnier said as he left the meeting.

Barnier told The Associated Press that now “more than ever, the Brexit is a school of patience, even a university of patience.”

No date was given for the political leaders' meeting. The leaders of the EU's 27 nations are holding a two-day summit in Brussels starting Thursday and are not keen for it to be overshadowed by Brexit.

The U.K. left the EU politically on Jan. 31 after 47 years of membership, but remains within the bloc’s tariff-free single market and customs union through Dec. 31. Reaching a trade deal by then would ensure there are no tariffs and quotas on goods exported or imported by the two sides, although there would still be new costs and red tape.

Failure to secure a trade deal would mean tariffs and other barriers that would hurt both sides, although most economists think the British economy would take a greater hit because the U.K. does almost half of its trade with the bloc.

While both sides want a deal, talks have stalled because they have fundamentally different views of what it entails. The EU accuses Britain of seeking to retain access to the bloc’s vast market without agreeing to abide by its rules. It fears Britain will slash social and environmental standards and pump state money into U.K. industries, becoming a low-regulation economic rival on the bloc’s doorstep — hence the demand for strict “level playing field” guarantees.

The U.K. government sees Brexit as about sovereignty and “taking back control” of the country’s laws, borders and waters. It claims the EU is making demands it has not placed on other countries with whom it has free trade deals, such as Canada, and is trying to bind Britain to the bloc’s rules indefinitely.

“Our friends have just got to understand the U.K. has left the EU in order to be able to exercise democratic control over the way we do things,” Johnson said during a visit Tuesday to a hospital where some of the world’s first COVID-19 vaccinations were being administered.

Trust and goodwill have been further strained by British legislation that breaches the legally binding Brexit withdrawal agreement Johnson struck with the EU last year.

Britain says the Internal Market Bill, which gives the government power to override parts of the withdrawal agreement relating to trade with Northern Ireland, is needed as an “insurance policy” to protect the flow of goods within the U.K. in the event of a no-deal Brexit. The EU sees it as an act of bad faith that could imperil Northern Ireland’s peace settlement.

The House of Lords, Parliament’s unelected upper chamber, removed the law-breaking clauses from the legislation last month, but the elected House of Commons restored them on Monday night.

As the parliamentary tussle continues, the British government has offered the bloc an olive branch on the issue, saying it will remove the lawbreaking clauses if a joint U.K.-EU committee on Northern Ireland finds solutions in the coming days.

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Cook reported from Brussels. Sylvain Plazy and Sam Petrequin in Brussels contributed to this story.

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