"We got engaged two weeks ago," the leading Republican's daughter Bristol, 19, said in an interview of the couple by the weekly magazine.
"It felt right, even though we don't have the approval of our parents."
Bristol and Levi, 20 famously called off their previous engagement two weeks after the birth of their son Tripp in December 2008.
NBC television's "Today Show" read the following statement from Sarah Palin and her husband Todd, after they found out, though not through their daughter:
"Bristol at 19 is now a young adult. We obviously want what's best for our children. Bristol believes in redemption and forgiveness to a degree most of us struggle to put in practice in our daily lives."
Bristol and Levi told Us magazine that they reconnected three months ago while working out a custody plan for their 18-month-old son Tripp
"I really thought we were over," Levi told Us Weekly.
"So when I went, I had no hope. I think we both just started talking -- and then we took Tripp for a walk."
Bristol said about the meeting: "When he left that night, we didn't hug or kiss, but I was thinking how different it was. He texted me: 'I miss you. I love you. I want to be with you again' ... I was in shock."
And she said she was nervous about how to break news of the impending nuptials to her mother, who in the months since the 2008 presidential elections has become arguably the most powerful and influential member of her Republican party.
"It is intimidating and scary just to think about what her reaction is going to be. Hopefully she will jump on board," Bristol Palin said.
Sarah Palin and Levi Johnston have had a tempestuous relationship, publicly trading insults and barbs in the media.
In the past few weeks however, Johnston has appeared in the media retracting some of the unflattering jibes against his future mother-in-law.
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