The mayor of Berlin has pleaded with Donald Trump not to build a wall along America's southern border with Mexico.

Michael Mueller said that such a wall would "destroy the lives of millions".

"Our city cannot look on without comment when a country plans to build a new wall," he said in a statement.

"We Berliners know best how much suffering was caused by the division of an entire continent with barbed wire and concrete. Do not go down this wrong path of isolation and exclusion."