Levi Johnston and Bristol Palin, the teenage daughter of Sarah Palin, have broken off their engagement.
The announcement came about 2 months after the couple had a baby.
Johnston, 19, told The Associated Press that he and 18-year-old Bristol Palin mutually decided "a while ago" to end their relationship.
He declined to elaborate as he stood outside his family's home in Wasilla, about 64 kilometres north of Anchorage.
He also said some details of the breakup, rumours of which had been swirling on the internet, were inaccurate.
Bristol Palin said in a statement issued through a spokeswoman for her mother's political action committee that she was "devastated".
"Unfortunately, my family has seen many people say and do many things to 'cash in' on the Palin name," she said. "Sometimes that greed clouds good judgment and the truth."
The two teens are the parents of a boy named Tripp, who was born on 27 December.
Sarah Palin revealed her daughter's pregnancy just days after being named John McCain's running mate on the Republican presidential ticket.
In an interview that aired on Fox News last month, Bristol Palin said her fiance saw the baby every day and described him as a "hands-on" dad.
The two had said they were considering a summer wedding.