The UK has a six-month deadline to resolve the Northern Ireland protocol row, with plans afoot for a state visit next year for Joe Biden to mark the 25th anniversary of the Good Friday agreement. Senior government sources said the date next April represented an “absolutely vital” moment to get the Northern Ireland executive up and running again, with unionist parties blocking the power-sharing institutions as part of a protest against post-Brexit trading rules. The Biden administration raised the protocol with Liz Truss in her first bilateral talks with the US president in New York on Wednesday, amid concerns in the White House that the Good Friday agreement could be under threat as a result of the row. In his televised opening remarks at the start of the meeting, signalling their significance, Biden told Truss: “We are both committed to protecting the Good Friday agreement of Northern Ireland. I’m looking forward to hearing what’s on your mind.” While the primary focus of the trip for Truss has been tackling Russian aggression in Ukraine, it raises concerns the new prime minister was letting the issue “drift”, despite her promises. Over the two days, she has declined to discuss the issue with the French president, Emmanuel Macron, and held a “behind closed doors” meeting with the European Commission chief, Ursula von der Leyen. Downing Street said that in the Biden meeting, which ran 15 minutes over, the two leaders had agreed that the “priority” was making sure the Good Friday agreement was upheld, “preserving the gains of peace” in Northern Ireland. Diplomats suggested that Biden could travel to the UK to mark the 25th anniversary of the Good Friday agreement, creating a deadline for the EU and the UK to resolve the issue. “If you look at the calendar you will conclude that next year might be an obvious reason to visit Europe if things come good,” one said. One senior government source said: “What we want to do is protect and restore the Good Friday agreement. I think the 25th anniversary next year is a key decision point but the big obstacle to that being the lack of an executive at the moment.” Downing Street has attempted to decouple the protocol row from Britain striking a coveted free trade deal with the US, with Truss admitting ahead of her visit that an agreement may not happen for years, despite it being hailed by Brexit supporters as one of the major potential benefits of leaving the EU. Within days of taking over, the White House warned Truss against “undoing” the Northern Ireland protocol, stressing that while there was no “formal linkage” between the issue and striking a free trade deal, it would not create a “conducive environment”. The government has vowed to secure changes to the protocol, either by way of a negotiated compromise with the EU or through controversial domestic legislation that would empower ministers to scrap the arrangements without the approval of Brussels. Political opponents have criticised the DUP boycott, which they said was hampering efforts to support families struggling amid the cost of living crisis. The executive has been suspended for three out of the last five years. One senior government source said: “Everyone needs to see that get up and running as soon as possible … the 25th anniversary is a key pivot moment, which is Easter next year. If you don’t have an executive [or] assembly by then that’s pretty bad all round.” Both sides have said in recent weeks that they are determined to find an agreed path for post-Brexit trade rules in Northern Ireland, with the UK demanding the removal of physical checks on farm produce and other goods. However, the UK has also insisted it will maintain the right to take unilateral action as an “insurance policy” in the event a solution cannot be found. Tony Blair has been involved in reassuring both EU nations and the US that the row over the post-Brexit trading rules in Northern Ireland was not a threat to the stability of the Good Friday agreement, according to British diplomats. One said: “Tony has certainly been explaining to the Europeans and the Americans that the British government have a real point on the trading aspects of the Northern Ireland protocol. He’s been explaining in a way that only he can, given his role in the Good Friday agreement. “He has been explaining why there’s no danger, why it’s not about the Good Friday agreement. It’s about communities. “And he’s been explaining why the EU’s proposals will not will not work. Now he doesn’t agree with the government on every point, but he certainly has been a helpful voice in that.” A spokesperson for Blair declined to comment.