The royal family announced on Saturday that Queen Elizabeth II’s funeral will take place on September 19, but exactly what the guest list will be remains up in the air. The Queen died on Thursday aged 96 after a historic 70-year reign. Buckingham Palace had long planned her death, after which her son, now King Charles III, immediately ascended the throne. The Queen’s coffin is being prepared to lie in state at Westminster Hall for four days before the funeral to allow the public to pay their respects. Officials predict more than a million people will attend. A formal funeral is expected to be held at Westminster Abbey, where the Queen was crowned and married Prince Philip in 1947. Around 2,000 people are expected, including Europe’s royal families and leaders from around the world. President Joe Biden said Friday that while he does not yet have details on the service, he will attend. It is unclear whether former US presidents will be on the guest list. CNN reported Friday that the U.K. is leaving that decision up to Biden. “I’ve been told by two diplomatic officials that Buckingham Palace leaves it up to each country,” said Jeff Zeleny, CNN’s chief national affairs correspondent, noting that former President Barack Obama invited George W. Bush, Bill Clinton and Jimmy. Carter to go with him to Nelson Mandela’s funeral in 2013. “So there is protocol for US presidents to call other presidents,” he continued. “Who knows, maybe in the spirit of forgiveness and giving President Biden will invite Donald Trump on Air Force One. I doubt that will happen, but I expect some type of bipartisan delegation.” Former President Donald Trump, for his part, was an ardent admirer of the Queen, whom he met on several official state visits during his presidency. Following the news of her death, Trump shared a long tribute to the Queen in a series of posts on Truth Social. “Melania and I will always cherish our time with the Queen and never forget Her Majesty’s generous friendship, great wisdom and wonderful sense of humour,” he wrote, adding: “God bless the Queen, she reigns forever in our hearts and may God keep her and Prince Philip in his constant care.” Trump also shared several photos of himself and the Queen smiling together during their visits. Trump and Biden, on the other hand, may be on more hostile terms than ever after the president’s Sept. 1 speech in which he said “MAGA Republicans” represented a danger to American democracy. While discussing whether or not Biden would invite Trump to the funeral, CNN’s Jake Tapper said he thought it would be a “smart” move for the president to invite him and see if he goes. “I don’t think former President Trump would want to be subservient to Air Force One, and I think he probably prefers his own plane anyway,” Tapper said.