Her Majesty the Queen will host a special luncheon for President Barack Obama when he visits the UK next month. The pair will dine privately at Windsor Castle, though the exact date is yet to be confirmed.
It is thought that Mr Obama will meet the Queen just a day or two after her 90th birthday, which falls on 21 April.
A White House spokesman said: "The visit will allow the president to offer his gratitude to the British government and people for their stalwart partnership with his administration and the American people throughout his presidency."
This will most likely be Mr Obama's final official trip to the UK as president of the United States. He will also hold a joint conference with Prime Minister David Cameron at 10 Downing Street.
Mr Obama and the Queen have met several times during the leader's presidency and the pair enjoy a warm personal relationship.
In May 2011, Barack and his wife Michelle made a trip to London and on the first day of their visit, the couple were guests of honour at a state banquet at Buckingham Palace. Hosted by the Queen, the lavish affair saw 171 guests present, including Kevin Spacey, Tom Hanks and director Tim Burton.
In her welcome speech the royal spoke of her "fond memories" of first meeting the Obamas ahead of the 2009 G20 conference in London. It was then, also in Buckingham Palace, that Michelle broke royal protocol and put her arm around the Queen – only to have the monarch return the gesture and hug her back.
For his part Mr Obama paid tribute to the Queen's "lifetime of extraordinary service to her nation and to the world". He also thanked her for the "warm friendship" she had extended and brought "warm greetings" from his daughters Malia and Sasha.
Barack and the Queen were last pictured together in June 2014 at the 70th anniversary for D-Day. The pair were joined by other leaders and dignitaries at Normandy, including President François Hollande, German Chancellor Angela Merkel and Queen Margrethe II of Denmark.