Joe Biden has been sworn in as the 46th US president, ending one of the most dramatic political transitions in American history. Kamala Harris became the first woman - and the first person of colour - to be made vice president. Also in the programme: Leaders from around the world have congratulated President Biden; and China has imposed sanctions on more than twenty members of the outgoing Trump administration. (Photo: Father Leo O' Donovan talks to President-elect Joe Biden during the inauguration of Joe Biden as US President in Washington. Credit: EPA).