Donald Trump has chosen not to fire Miss USA Tara Conner amid reports she has visited bars, though she is not yet 21.

"I've always been a believer in second chances -- Tara is a good person," Trump said in a news conference Tuesday. "Tara is going to be given a second chance."

SLIDESHOW: 2006 Miss USA Contestants

As part of staying on as Miss USA, Conner has agreed to enter rehab.

Trump said, "Until this morning, I didn't know which way it was going to go." But upon meeting her in his office, he said that he saw her "good heart" and that she "got caught up in the whirlwind that all know as New York."

Conner won the title in April and has been living in New York. Recent media accounts of heavy drinking brought a storm of criticism, since she was underage at the time. She turned 21 on Monday.

"He didn't have to keep me around," a tearful Conner said at the news conference.

"He's a very, very compassionate person, and I obviously learned that today. I plan on walking out of this being the best Miss USA you've ever seen," Conner said, motioning to Trump. "Thank you, you'll never know what this means to me. And I swear I'll never let you down."

In no uncertain terms, Trump spelled out Conner's fate if she stumbles again.

"If she makes the slightest mistake from here on, she will be replaced," Trump said.

Trump said that he believed Conner can be a good example for "troubled people" -- people who have "trouble with alcohol, trouble with life."

Conner has been competing in pageants since age 4. The Kentucky native said at the news conference that she has wanted to be Miss USA since she was 13.

SLIDESHOW: Images of Tara Conner

After winning the Miss USA title in April, Conner finished fourth in the Miss Universe pageant in July.

If Conner had been dethroned, her title would have been taken over by first runner-up Miss California Tamiko Nash.

In 2002, Miss Russia, Oxana Fedorova, won the Miss Universe pageant but was stripped of her title after violating her contract.

Trump began Tuesday's news conference by saying that he fired Fedorova "for doing a bad job."