On Sunday afternoon, the President and First Lady Jill Biden will pay their respects to the Queen, whose coffin lies in state at Westminster Hall, before signing a book of condolences and attending a reception for leaders hosted by Britain’s new king. Charles. III. For Biden, it is a moment to reflect on a monarch who embodied his commitment to public service and whose life shaped the great historical events of the past 100 years. Biden and the Queen first met in 1982 when, as a young senator, Biden’s own Irish-American mother instructed him: “Don’t bow to her.” He did not bow then, nor when he met the Queen as President last year while attending a Group of 7 summit in England. But his respect for a woman whose steadiness on the world stage over the past century was unparalleled was clear. “She was a wonderful lady. We are so glad to have known her,” Biden said the day she died. The Queen’s surprise decision last year to travel to the Cornish coast to meet world leaders at the G7 summit was a sign of her desire to remain engaged in global affairs. Later that week, when he hosted Biden and first lady Jill Biden for tea at Windsor Castle, he asked about two authoritarian leaders, Presidents Xi Jinping of China and Vladimir Putin of Russia, the President told reporters later. “He was so curious. He wanted to know everything about American politics, what was going on. So he put us at ease,” Jill Biden said recently in an interview with NBC. At Sunday afternoon’s reception, Biden will see Charles for the first time since becoming king. The two men had met before and spoke last week by phone. As the Prince of Wales, Charles has been a passionate campaigner on a number of issues that Biden has also championed, including the fight against climate change. It remains to be seen how involved the new King will be in these matters going forward. Relatively close in age — Charles is 73, Biden 79 — the two men have a shared experience of being in the public eye for decades before assuming their current roles as heads of state. In his call with the king, Biden “conveyed the great admiration the American people have for the Queen, whose dignity and stability have deepened the enduring friendship and special relationship between the United States and the United Kingdom,” the White House said . “President Biden has expressed his desire to continue a close relationship with the king.” Security in the British capital is at its highest level in memory as Biden and dozens of other world leaders gather to remember the late queen, who met 13 sitting US presidents during her reign. White House aides declined to provide specific security details for the President’s visit, but say they are working well with their British counterparts to ensure presidential security requirements are met. Plans for the queen’s funeral have been in place for years, giving US advisers greater insight into exactly what will happen in the coming days as they make security arrangements. The White House said it received an invitation only for the President and First Lady, leading to a slimmed-down American footprint. Biden traveled with his national security adviser, communications director and other personal aides on Air Force One in London. When reports emerged last week that world leaders would have to board a bus for the funeral, US officials were skeptical and rejected the suggestion that Biden travel to Westminster Abbey by coach. In 2018, when other world leaders traveled together in a bus to a World War I memorial in Paris, then US President Donald Trump traveled separately in his own vehicle. The White House explained at the time that the separate trip was made “due to security protocols.” The Queen’s death came at a time of economic and political turmoil for the United Kingdom. A new prime minister, Liz Truss, took office after months of uncertainty following her predecessor Boris Johnson’s decision to resign. Truss invited several visiting world leaders to meet individually at 10 Downing Street this weekend. In the role for just over a week, it will be the first time Truss will meet face-to-face with many of her foreign counterparts. While her office initially said Biden would be among the leaders visiting Downing Street, it was later announced Truss and the President would meet for formal bilateral talks on Wednesday on the sidelines of the United Nations General Assembly in New York. A number of issues are currently testing the US-UK “special relationship”, which has been repeatedly announced in the days since the Queen’s death. Just two days after Truss traveled to Balmoral Castle in Scotland to formally accept the Queen’s appointment as prime minister, the long-reigning monarch died. Since then, the country has been in official mourning. Truss inherited a deep economic crisis, fueled by high inflation and rising energy costs, leading to fears that the UK could soon enter a prolonged recession. The challenges have been compounded by Russia’s invasion of Ukraine, which has caused volatility in oil and gas markets. While few in the Biden administration shed tears over Johnson’s resignation — Biden once described him as Trump’s “physical and emotional clone” — the US and UK have become deeply aligned in their approach to Russia under his leadership. White House officials expect cooperation to continue under Truss, even as he comes under pressure to ease economic pressures at home. Less certain, however, is whether Trudeau’s tough approach to Brexit will worsen relations with Biden. The President has taken a personal interest in the specific issue of the Northern Ireland Protocol, a post-Brexit agreement that requires additional checks on goods traded between Northern Ireland and the rest of the UK. The rules were designed to keep the border between Northern Ireland and the Republic of Ireland open and avoid a return to sectarian violence. But Truss has moved to rewrite those rules, causing deep concern in both Brussels and Washington. Biden, who makes frequent references to his Irish ancestry, has been clear about his views on the issue, even though it does not directly concern the United States. Democrats in Congress have expressed similar concern over any steps that could reignite the conflict in Northern Ireland. In their first phone call as counterparts earlier this month, Biden raised the issue with Truss, according to the White House. A US readout of their conversation said they discussed a “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”.