Barack Obama has officially endorsed Hillary Clinton to succeed him as president as he tries to unite the Democrats between now and Novermber to take on the challenge of Republican candidate Donald Trump. It makes Clinton the first female presidential nominee of a major political party.

In a video put on the Clinton campaign's website, Obama said: "I don't think there's ever been someone so qualified to hold this office." Speaking to Reuters, Clinton said Obama's endorsement "means the world".

It followed a meeting between Obama and Clinton's rival Bernie Sanders where the Vermont senator said he would back Clinton but only after the Washington DC Democratic caucus on Tuesday 14 June.

Obama and Hillary
Barack Obama has endorsed Hillary Clinton, pictured here in Hollywood, California in January 2008Reuters

Although Sanders is yet to concede publicly that the race is over, he told reporters: "I look forward to meeting with her in the very near future to see how we can work together to defeat Donald Trump and to create a government which represents all of us and not just the 1 per cent."

Only on Tuesday 6 June, Sanders insisted that he would continue the fight and he will hold a major rally near the Capitol building. Obama will campaign with Clinton in Green Bay, Wisconsin with White House Press Secretary Josh Earnest adding that no more campaign events are scheduled yet.