"He is a great publicity-seeker — and at a time when the Republican Party hasn't really figured out what it's for as opposed to what it's against," Obama said of Trump during an interview on CBS' "60 Minutes" program airing on Sunday night.
Opinion polls put Trump at the front of a crowded Republican field seeking the party's nomination for the November 2016 presidential election.
The billionaire real estate mogul and television personality has aroused controversy with his provocative remarks on illegal immigration. He has promised to build a wall on the U.S.-Mexico border and to deport the estimated 11 million illegal immigrants already in the United States.
Obama said Trump had tapped into something that "exists in the Republican Party that's real. I think there is genuine anti-immigrant sentiment in the large portion of at least Republican primary voters."
"He is, you know, the classic reality TV character," the Democratic president said, adding it was not surprising Trump had received a lot of attention in the campaign's early stages.
Asked if he thought Trump would eventually disappear from the race, Obama replied: "I'll leave it up to the pundits to make that determination. I don't think he'll end up being president of the United States."
Obama also said in the interview that he did not know about Democratic presidential candidate Hillary Clinton's use of a private email server while she was his secretary of state but that it did not pose a national security problem.
"She made a mistake. She has acknowledged it," he said.
"I do think that the way it's been ginned up is in part because of politics. And I think she'd be the first to acknowledge that maybe she could have handled the original decision better and the disclosures more quickly."
Discussing Joe Biden's possible entry into the Democratic race, Obama called him one of the finest vice presidents ever and said: "If you're sitting right next to the president in every meeting and ... wrestling with these issues, I'm sure that for him he's saying to himself: 'I could do a really good job.'"
Asked if he thought he himself could be re-elected if not constitutionally barred from a third term, Obama replied: "Yes."