Billionaire Donald Trump promised to "make America great again" as the property magnate launched his campaign to succeed Barack Obama as president of the US.
To meet transparency rules, Trump revealed that he is worth $8.7bn (£5.7bn) as he made his intentions to gain the Republican nomination public.
The right-winger was introduced by his daughter Ivanka at the businessman's eponymous Trump Tower in New York.
The Apprentice star was greeted by cheers as he walked to the stage, with Neil Young's Keep On Rockin' In The Free World playing in the background.
Trump claimed, in a wide-ranging speech, that the US had become a "dumping ground for everybody else's problems" and that his country was losing out to China and Japan in the world race.
The 69 year old promised to be the "greatest jobs president that God ever created" and alleged that Mexico was sending "migrants with lots of problems... including rapists" to the US.
He added: "They are not sending us not the right people. We have no protection. We don't know what's happening and it's [got to] stop, and it's gotta stop fast."
But the celebrity has a political mountain to climb if he wants to get inside the White House as he faces tough competition for the Republican ticket, including from former Florida governor Jed Bush.
Jed, 62, the younger brother of George W Bush and son of George HW Bush, argued that "America deserves better" when he launched his campaign on 15 June.
Meanwhile, Hillary Clinton is the frontrunner in the race to win the Democratic Party nomination for the 2016 presidential contest.
The former secretary of state, 67, said in a campaign video message: "Everyday Americans need a champion. And I want to be that champion. So I'm hitting the road to earn your vote — because it's your time. And I hope you'll join me on this journey."