He served as a Labour MP for Hartlepool from 1992 to 2004, during which time he served as secretary of state for Northern Ireland and business secretary.
His appointment comes ahead of the inauguration of President-elect Donald Trump in January.
A government source said: “The fact the prime minister has chosen to make a political appointment and sent Lord Mandelson to Washington shows just how importantly we see our relationship with the Trump administration.
“We’re sending someone close to the prime minister with unrivalled political and policy experience, particularly on the crucial issue of trade. He’s the ideal candidate to represent the UK’s economic and security interests in the USA.”
Both the White House and Trump campaign were notified of the appointment in advance.
Ch Supt David Robertson said: "Cancelling such an event was a difficult decision for the organisers, but public safety takes priority, so we fully support this
Referees will announce any video assistant referee decisions to football supporters inside stadiums in England for the first time during the Carabao Cup semi-fi
Stoke-on-Trent saw the largest growth in house prices in the UK in 2024, according to a lender's research.The study from Halifax found the city's average house
Mr Hill founded the Glasgow-based MOJO (Miscarriage of Justice Organisation) after his release, helping others who were imprisoned despite being innocent of the