The new Prime Minister of the United Kingdom, Liz Truss, said on Wednesday that she hoped negotiations with the EU would help resolve a disagreement over post-Brexit trade in Northern Ireland.

"My preference is for a negotiated solution," she told MPs in parliament, in her first appearance as premier since formally taking office on Tuesday. "But it does have to deliver all of the things we set out in the Northern Ireland Protocol Bill," she added. 

Truss pushed a measure in her previous post as Foreign Secretary, which proposes repealing portions of the agreement reached by London with Brussels as part of the UK's exit from the EU.

Read next: Truss insider 'confident' energy bills will be frozen in UK

Despite EU warnings, the parliament is currently debating that it violates international law and could result in retaliatory trade restrictions.     

The UK government opposes internal border checks on goods traveling from England, Scotland, and Wales to Northern Ireland.

The EU has mandated checks to prevent goods from entering the European single market through the neighboring member state the Republic of Ireland.

The removal of hard border infrastructure between Northern Ireland and the republic was a requirement of the 1998 peace agreement, which ended 30 years of conflict over British authority.

Read next: EU takes legal action against UK for breaching N.Ireland agreement

However, pro-UK unionist groups argue that the checks isolate Northern Ireland from the rest of the UK, increasing the danger of a united Ireland.

Truss said her "number one priority" was "protecting the supremacy" of the peace deal, against a backdrop of concern from US President Joe Biden's administration in Washington. She committed to fixing the issue that has caused unionist parties to quit Belfast's power-sharing devolved government.  

"I want to work with all of the parties in Northern Ireland to get the executive and the assembly back up and running," Truss added.      

"But in order to do that, we do need to fix the issues of the Northern Ireland protocol, which has damaged the balance between the communities in Northern Ireland."     

"I'm determined to get on with doing that and I'm determined to work with all parties to find that resolution." 

What is #Article16 that #LizTruss might put into effect if she takes office?#UnitedKingdom pic.twitter.com/ZaMKr8DBHB

— Al Mayadeen English (@MayadeenEnglish) August 28, 2022