Getty Images Obama: "Trump can finally get back to the issues that really matter, like "Did we fake the moon landing"?
Media playback is unsupported on your device
Video

Obama pokes fun at Donald Trump

President Obama has been mixing comedy with some early campaigning at the White House correspondents' annual dinner.

After weeks of attacks from his would-be Republican challenger Donald Trump, he joked about having to release his birth certificate to prove he was born in America.

Daniel Griffiths reports.

Go to next video: Trump on Obama's birth certificate