Jill Biden will attend the coronation of King Charles on behalf of US president Joe Biden at the ceremony held on Saturday May 6.
On Tuesday, Mr Biden called Charles to inform him that he will not be attending the investiture of the new monarch and told him the First Lady will take his place.
The president congratulated him ahead of his coronation, which will be held at Westminster Abbey, and also expressed his desire to meet Charles in the UK at a future date.
A White House statement read: "President Joseph R Biden Jr spoke today with King Charles III, underscoring the strength of the relationship between our countries and the friendship between our peoples.
"The president congratulated the King on his upcoming coronation and informed him that First Lady Jill Biden looks forward to attending on behalf of the United States.
"The president also conveyed his desire to meet with the King in the United Kingdom at a future date."
The decision for Mr Biden not attending the coronation has raised some eyebrows, especially after the president and his wife travelled to London for the funeral of the late Queen last September.
Both US and British officials insist that their 'special relationship' remains intact, however, the event comes at a sensitive time.
Mr Biden has openly acknowledged his love towards Ireland and the ceremony takes place shortly after the US president's expected visit to Northern Ireland and the Republic of Ireland ahead of 25th anniversary of the Good Friday Agreement between the neighbouring countries.
Mr Biden is proud of his Irish heritage and has not shirked from voicing his opinions on the country's affairs, such as urging Britain to respect the Northern Ireland Protocol.
The visit has not been confirmed by White House officials but he was invited by British Prime Minister Rishi Sunak when they met in San Diego last month, which the president accepted.
During the trip, he is expected to visit his family members - distance cousins the Finnegans - who live in Counties Louth and Mayo.
The official celebration of the Good Friday Agreement, which ended 30 years of sectarian violence between pro-Ireland Catholics and pro-Britain Protestants, will see leaders such as Charles, Sunak, Bill Clinton and former secretary of state Hillary Clinton. Then-President Bill Clinton helped negotiate the agreement.
Prince George has been handed a central role for the King’s Coronation as a Page of Honour.
The nine-year-old future king will walk behind his grandad, helping to carry his robes as he enters and leaves Westminster Abbey.
The King and George’s father, Prince William, were keen for the young prince to have an important role on May 6 and decided he will be front and centre.
George and seven other boys named Pages of Honour will "attend their majesties", the King and Queen, during the service.
They are primarily responsible for carrying their long, heavy robes. The honour is usually granted to teenage sons of members of the nobility and gentry, and especially of senior Royal Household members.
The boys are either family friends or relatives of Charles and Camilla. The King’s other Pages of Honour will be Lord Oliver Cholmondeley, 13, Nicholas Barclay, 13, and Ralph Tollemache, 12.
The Queen Consort’s Pages of Honour will be her grandsons, twins Gus and Louis Lopes, and Freddy Parker Bowles, along with great-nephew, Arthur Elliot.
