WASHINGTON (REUTERS) - US President Barack Obama discussed the British vote to leave the European Union in separate phone calls on Friday with British Prime Minister David Cameron and German Chancellor Angela Merkel, the White House said.

Obama assured Cameron that the special US relationship with Britain and Britain's membership in Nato remained vital cornerstones of US policy, the White House said in a statement.

Obama and Merkel both said they regretted the decision of British voters but respected the will of the British people, the statement said.