Irish Prime Minister Leo Varadkar pledged Sunday to intensify efforts with his British counterpart Rishi Sunak to restore power-sharing government in Northern Ireland and hopes to break the deadlock there in the next few months.

The Democratic Unionist Party (DUP) has said it will not drop a yearlong boycott of the devolved assembly in protest at post-Brexit trade rules without further changes to a deal struck by the United Kingdom and the European Union in February to ease the trade barriers.

London has said it will not renegotiate any part of its new agreement.

“We put a huge amount of effort in the last few months into getting an agreement on revisions and reforms to the protocol,” Varadkar told national broadcaster RTE, referring to the checks on goods between Northern Ireland and the rest of the U.K. that has angered many pro-British unionists.

“The next piece now is deep engagement with the British government and also with the five parties in Northern Ireland to try and get the institutions up and running again, and certainly over the next few weeks I’ll be intensifying my contacts with Prime Minister Sunak.”

Varadkar said he would work toward restoring the mandatory power-sharing government “in the next few months,” noting that May’s local council elections and the annual marching season in July – which often sparks sectarian tensions – could make an agreement more difficult in the short term.

The DUP, at odds with opinion polls that suggest most Northern Irish voters support the revised Brexit deal, has said its concerns over the continued role of EU law and Northern Ireland’s place in the U.K.’s internal market must be addressed.

The latest suspension of the assembly is casting a shadow over Monday’s 25th anniversary of the Good Friday Agreement. U.S. President Joe Biden will visit Northern Ireland on Tuesday to mark the peace accord that ended three decades of bloodshed.

Power-sharing has collapsed several times for different reasons since its introduction as part of the peace deal, each time being restored after long political talks. The most recent lasted from 2017 to 2020.