U.S. President Barack Obama exacted his revenge Saturday after weeks of attacks from his would-be Republican challenger Donald Trump, joking that the billionaire businessman could bring change to the White House, transforming it from a stately mansion into a tacky casino with a whirlpool in the garden.

With Trump in attendance, Obama used the White House Correspondents' Association annual dinner to mock the reality TV star's presidential ambitions. The president said Trump has shown the acumen of a future president, from firing Gary Busey on a recent episode of Celebrity Apprentice to focusing so much time on conspiracy theories about Obama's birthplace.

After a week when Obama released his long-form Hawaii birth certificate, he said Trump could now focus on the serious issues, from whether the moon landing actually happened to "where are Biggie and Tupac?"

"No one is prouder to put this birth certificate matter to rest than 'the Donald,'" Obama said, referring to Trump's claims the same day that he was responsible for solving the issue.

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Donald Trump arrives for the White House Correspondents' Dinner on Saturday, where he absorbed a few jibes from U.S. President Barack Obama. ((Alex Brandon/Associated Press))

For Trump's decision to fire actor Busey instead of rock singer Meat Loaf from his TV show earlier this month, Obama quipped: "These are the types of decisions that would keep me up at night. Well handled, sir."

Finally, Obama showed a screen with his vision of how Trump could bring change to the White House. "Trump" was prominently displayed in glittery letters and waitresses could be seen with cocktails on a Jacuzzi-augmented front lawn.

Obama and Trump found themselves in the same room after an intense week of attacks from Trump, who has piggybacked on the birther conspiracies and even Obama's refusal to release his university grades to raise the profile of his possible presidential bid.

And the birth certificate was clearly the key punchline for the evening, which typically offers the president a chance to show off his humorous side and a town consumed by politics and partisanship to enjoy a light-hearted affair.

Obama's presentation started after the playing of wrestler Hulk Hogan's patriotic anthem, Real American. Images of Americana from Mount Rushmore to Uncle Sam were shown on the screen, alongside the president's birth certificate. And then he offered to show his live birth video, which turned out to be a clip from the Disney film The Lion King.

On the serious side, Obama took time to thank the troops for their service overseas and noted that the people of the South, especially Alabama, have suffered heart-wrenching losses.

"The devastation is unbelievable and it is heartbreaking," the president said. He encouraged the journalists in the room to help tell the stories of those who have been hurt by the storms and saluted those who lost their lives while covering the news.