The former US president arrived in London for an unannounced visit to see the UK PM.
Barack Obama waved to the media but was tight-lipped as he walked into 10 Downing Street on Monday afternoon.
He joked that was “tempted” to talk to the BBC’s Helen Catt when he left an hour later, but said no more, although he seemed a little confused as where to his vehicle was. Mr Sunak did not appear publicly with him.