ITV News' Libby Wiener reports from Sao Paulo in Brazil where Prime Minister David Cameron is on a two-day visit.
The Conservative, who appeared on America's Late Show with David Letterman on Wednesday night, was quizzed by the veteran host over his knowledge of British history.
More top news
An internet troll who told a Jewish Labour MP she would "get it like Jo Cox" is facing jail for a second time.
Detectives investigating the attempted abduction of an RAF serviceman at Marham have released e-fit images of the suspects.
The National Trust has published a list of 50 things for children to do before they turn 11 and three-quarters, such as climbing a tree.