BRUSSELS — European Commission Vice-President Maros Sefcovic and the United Kingdom Brexit minister David Frost will hold talks Thursday in Brussels to discuss Northern Ireland trade rules, the EU said on Wednesday.

The meeting will take place a month after the EU started legal action against the United Kingdom, arguing the former member did not respect the conditions of the Brexit withdrawal agreement and violated international law.

EU Commission spokesman Daniel Ferrie said Sefcovic and Frost will have an informal meeting to “take stock of ongoing technical work” and “to provide a political steer for both teams on outstanding issues.”

Both sides are trying to find an agreement on trade rules in Northern Ireland amid rising tensions in the small territory where Britain’s exit from the European Union has unsettled an uneasy political balance . Earlier this month, Protestant and Catholic youths in Belfast hurled bricks, fireworks and gasoline bombs at police and each other during a week of violence.

Northern Ireland is part of the United Kingdom but remained part of the EU’s single market for goods after Brexit to avoid checks between Northern Ireland and EU member Ireland because an open Irish border has helped underpin the peace process. But unionists say the new checks amount to the creation of a border between Northern Ireland and the rest of the UK — something they fear undermines the region’s place in the United Kingdom.

In March, the UK decided to unilaterally extend a grace period until October on checks for goods moving between Britain and Northern Ireland, a decision that led the EU to issue a formal notice to its former member. The UK had been given one month to respond.