German Chancellor Angela Merkel has called the UK's decision to leave the EU a "warning shot". She said in a speech at a Christian Democratic Union meeting on Friday that the EU needs to make decisions more quickly rather than agree new treaties.

"The fact that Great Britain wants to leave the European Union is a warning shot to all of us to reconsider once again: What does Europe mean for us? What must Europe change to be successful in the eyes of the people? I think we have the chance to focus on that," Angela Merkel said.