Britain’s new prime minister, Liz Truss, said on Wednesday she hoped talks with the EU could help resolve a post-Brexit trade dispute in Northern Ireland.

“I prefer a negotiated solution,” she told MPs on her first appearance as prime minister since taking office on Tuesday.

“But it has to deliver all the things that we have set out in the Northern Ireland Protocol Bill,” she added.

The bill, led by Truss in her former role as Foreign Secretary, proposes scrapping parts of the deal London signed with Brussels as part of Britain’s exit from the bloc.

It is currently snaking through Parliament, despite warnings from the EU that it violates international law and could trigger trade sanctions in retaliation.

The UK government opposes internal border controls on goods entering Northern Ireland from mainland Britain – England, Scotland and Wales.

The EU has imposed controls to prevent goods from entering the European single market via neighboring Ireland.

The removal of hard border infrastructure between Northern Ireland and the Republic was a condition of the 1998 peace accord that ended 30 years of violence against British rule.

But pro-British union parties say the controls are pulling Northern Ireland apart from the rest of the UK and raising the risk of a united Ireland.

Truss said her “top priority” was to “protect the supremacy” of the peace deal, amid concerns from US President Joe Biden’s administration in Washington.

She promised to solve the problem, which has led to union parties withdrawing from the power-sharing government in Belfast.

“I want to work with all parties in Northern Ireland to get the Executive and Assembly back up and running,” Truss added.

“But to do that we need to resolve the problems of the Northern Ireland Protocol, which has damaged the balance between communities in Northern Ireland.

“I am committed to moving forward with this and I am committed to working with all parties to find this solution.”