He took a similarly tough stance on Libyan leader Moammar Gadhafi, who is repelling rebel forces in his war-torn nation. The U.S. is considering pushing the United Nations to broaden the use of force against Gadhafi beyond simply a no-fly zone.
Speaking of Gadhafi's brutal use of force against civilians and rebels in Libya, Trump said he'd be for a "surgical strike" on Gadhafi.
"If we could surgically strike and stop that from happening, I'd be for it, but not to get into a war," he said, adding that he believed the president had missed a chance to do just that.
Speaking about the president, Trump – in line with "birthers" who question the president's citizenship – said he, too, had his doubts that Obama was born in the U.S.
"Everybody that even gives a hint of being a birther … even a little bit of a hint, like, gee, you know, maybe, just maybe this much of a chance, they label them as an idiot. Let me tell you, I'm a really smart guy," he said.
He explained the source of his doubt: "He grew up and nobody knew him. You know? When you interview people, if ever I got the nomination, if I ever decide to run, you may go back and interview people from my kindergarten. They'll remember me. Nobody ever comes forward. Nobody knows who he his until later in his life. It's very strange. The whole thing is very strange," he added.
Trump wasn't kinder to his potential competition for the Republican Party nomination for president.
On Mitt Romney: "Well, he doesn't seem to resonate. Good man, nice guy, but he doesn't seem to resonate," Trump said.
On Tim Pawlenty: "I really think he's a fine guy. I've watched him, but I don't think he's going to captivate the votes."
On Haley Barbour: "I know him. I like him. I don't want to say one way or the other, you know, what's going to happen with him. But, you know, I just love him where he is."
On John Huntsman: "He sent me a beautiful Christmas card. I don't know him. I do say this with John Huntsman. When you work for somebody else, as he has worked for Barack Obama, you don't then leave and run against that person. It's very disloyal. I don't like that."
On Mike Huckabee: "I really like him. I think he's the kind of guy that maybe could really get some votes … ."
On Rick Santorum: "He lost his Senate race. How do you lose a Senate race and then all of a sudden show up and start running for president? You know, he's a nice guy … but I don't think he has a chance."
On Sarah Palin: "An amazing woman. You know, she gets knocked by so many people and she just keeps getting back up and up."
Trump added that he believed Palin had always been "underrated." Even though he acknowledged that polls said Palin wouldn't beat Obama in the next presidential election, he said she has "a very, very strong following."
Trump said he disagreed with the perception that Palin is unprepared to be president.
"She was the governor of a great state. She did fine as the governor. I think personally she made a tragic mistake when she left early … She did a good job as governor," he said. "And she's a tough cookie. I think she's more qualified than Barack Obama was when he became president."
Trump even had an opinion on the latest Hollywood showdown involving actor Charlie Sheen, who was fired from the hit sitcom "Two and a Half Men" following bizarre rants and questionable behavior.
Trump said he knew Sheen and his ex-wife, Brooke Mueller. He said Mueller's parents were members of Mar-a-Lago, an exclusive estate in Palm Beach, Fla.
"I told the parents, don't let your daughter marry him. I think he's wonderful, but he's a disaster. Don't let your daughter marry him," he said.