President George W. Bush began to recount a joke at the annual event, where US leaders are expected to show their humorous side, when he was "interrupted" by Laura Bush.

"I've been attending these dinners for years and just quietly sitting there. Well, I've got a few things I want to say for a change," she said, to great applause.

"George always says he's delighted to come to these press dinners. Baloney! He's usually in bed by now," she said. "I said to him the other day, George, if you really want to end tyranny in the world, you're gonna have to stay up later."