Donald Trump takes up role as 45th US president
Donald Trump has said he is honoured to be serving the "great American people", as he takes up the mantle of the 45th President of the United States.
One of his first jobs after formally taking office was to sign an executive order on Obamacare.
Later he visited the CIA headquarters in Langley, Virginia where, in a speech to CIA officers, he berated the media saying they had purposefully played down the number of people who attended his inauguration ceremony.