The European Union will get a fresh chance on Friday to see whether the U.K. stance in their post-Brexit negotiations over Northern Ireland is wavering, where a potential deal on medicines may signal a path to a broader compromise that could avert a trade war.

European Commission Vice-President Maros Sefcovic and U.K. Brexit Minister David Frost meet in Brussels on Friday to take stock of a week of intensive talks focused on easing the flow of medicines between mainland Britain and Northern Ireland, along with a broader range of customs and food inspection issues. A deal on medicines would give fresh impetus to the wider talks and temper fears that the U.K. might imminently quit the negotiations.

Britain insists it is as ready as ever to take unilateral action over Northern Ireland and trigger Article 16 of the Northern Ireland protocol, but the EU has become more optimistic in recent days about the prospects of reaching a deal. The European Commission briefed ambassadors on Wednesday that its threat to terminate the wider Brexit trade deal if Britain acts unilaterally appeared to make the U.K. appeared more willing to engage in the talks, according to a diplomatic note seen by Bloomberg.

On Thursday, the U.K. also appeared to take a more moderate stance over the issue of the role of the European Court of Justice in Northern Ireland, an area that has threatened to cause a breakdown in the negotiations. Speaking to the House of Lords, Frost acknowledged that the ECJ would continue to have a role in interpreting EU law in the region, a strong contrast to his remarks on Oct 25 that Britain was “not interested” in keeping the ECJ “in by some other name, at one remove or in some other way” concerning Northern Ireland.

“For as long as EU laws apply in Northern Ireland, then no doubt the court will continue to assert that right,” Frost said Thursday. “It is the settlement of disputes that is the difficulty here.”

But when pressed on whether the U.K. is in fact more open to compromise on Northern Ireland, Britain pushed back on the idea that anything has changed in their approach to the negotiation.

“I would suggest that our friends in the EU don’t interpret the reasonable tone that I usually use in my discussions with them as implying any softening in the substantive position,” Frost said. “Whatever messages to the contrary the EU may think they’ve heard or read, our position has not changed.”

A breakthrough on medicines would be particularly significant given a mood of distrust that has pervaded the talks so far, with some in the EU concerned that Britain hasn’t negotiated over Northern Ireland in good faith and is simply biding its time before triggering Article 16 of the protocol.

Article 16 allows either side to unilaterally suspend parts of the agreement in the event of diversion of trade or serious societal or economic difficulties. Britain argues these conditions have been met, due to a reduction in trade caused by new customs processes on goods crossing the Irish Sea.

The U.K.’s complaint about post-Brexit barriers to selling medications in Northern Ireland has been seen as the easiest element to resolve in the broader dispute. The EU has offered to allow medications, including generics, to be brought in from the U.K. without going through any additional checks or regulatory hurdles when they reach Northern Ireland.

Even so, the U.K.’s Northern Ireland Secretary Brandon Lewis reinforced Frost’s message, denying any watering down in Britain’s stance.

“We haven’t stepped back from the idea of triggering Article 16,” Lewis said Thursday in an interview in London. “Our focus at the moment is around these ongoing negotiations to try and get a solution, but we are also crystal clear: That can’t go on forever.”