The transatlantic relationship could be strained if Mrs Truss goes ahead with the plan to bypass parts of the Protocol, with Mr Biden proud of his Irish roots and keenly interested in the issue. According to the White House account of the call, the two discussed their “shared commitment to protecting the gains of the Belfast/Good Friday Agreement and the importance of reaching a negotiated agreement with the European Union on the Northern Ireland Protocol ». The White House said the leaders also discussed the importance of continuing to work closely on global challenges, including supporting Ukraine as it defends against Russian aggression, addressing challenges posed by China, preventing Iran from acquiring a nuclear weapon and ensuring sustainable and affordable energy sources”. A Downing Street spokesman said the pair reflected the “enduring strength” of the special relationship between the UK and the US. “The prime minister looked forward to working closely with President Biden as leaders of free democracies to address common challenges, particularly the extreme economic problems unleashed by Putin’s war,” he said. “The Prime Minister and President Biden reflected on the enduring power of the special relationship. They agreed that the partnership between our countries, strengthened by our shared values, was vital to the defense and promotion of freedom and democracy in the world. “They have agreed to build on these ties, including by advancing our deep defense alliance through NATO and Aukus.” Earlier, Mr Biden was the first world leader to congratulate Ms Truss on her new post. As Mrs Truss finished her speech and officially entered Downing Street, the US president tweeted: “Congratulations to Prime Minister Liz Truss. “I look forward to deepening the special relationship between our countries and working closely together on global challenges, including continued support for Ukraine as it defends itself against Russian aggression.”