Sept. 1 (Bloomberg) -- Republican vice presidential candidate Sarah Palin's 17-year-old daughter is pregnant, her campaign said in a statement today.

The daughter, Bristol, will have the baby and marry the father of the child, according to the statement, which was released on the first day of the Republican National Convention in St. Paul, Minnesota.

``We're proud of Bristol's decision to have her baby and even prouder to become grandparents,'' Palin, the governor of Alaska, and her husband, Todd, said in the statement. ``As Bristol faces the responsibilities of adulthood, she knows she has our unconditional love and support.''

Republican presidential candidate John McCain picked Palin, 44, as his running mate last week. The Palins have four other children.

Palin has had no public events since last night when she campaigned with McCain in O'Fallon, Missouri. Today she is in Minnesota preparing for the speech will give to the convention on Sept. 3.

McCain advisers Stephen Schmidt and Mark Salter told reporters in St. Paul today that the campaign learned of Bristol's pregnancy when they vetted her mother.

``Many American families have experiences like this,'' Salter said. ``Unfortunately, it has to play out in the public spotlight.''

`Dirty, Nasty Smears'

Schmidt said the campaign decided to disclose the information because of repeated media inquiries about ``dirty, nasty smears'' on the Internet that Bristol may actually be the mother of Sarah Palin's youngest child, Trig.

``It's a private family matter,'' Schmidt said.

Democratic presidential nominee Barack Obama, campaigning today in Monroe, Michigan, said Palin's children should be ``off limits'' and cited his own mother, who gave birth to Obama when she was 18.

``This shouldn't be part of our politics, it has no relevance to Governor Palin's performance as a governor or her potential performance as a vice president, and so I would strongly urge people to back off these kinds of stories,'' Obama told reporters.

Obama also said his campaign wasn't involved in spreading rumors that Bristol was Trig's mother.

``We don't go after people's families,'' Obama said. ``If I ever thought that there was somebody in my campaign that was involved in something like that, they'd be fired.''

Church Contact

The McCain campaign has contacted the church attended by the Palins and asked them to be respectful of the family, Wasilla Bible Church Executive Pastor Ashley Brown and Senior Pastor Larry Kroon, said.

``All I'll say is that Bristol's a young lady,'' Kroon said. ``We care about her and want to support her and the family.''

Brown said the call today was the first time McCain's campaign had contacted him.

Conservative Republicans said news of Bristol Palin's pregnancy doesn't affect their wholehearted support of her mother. They expressed approval that she is carrying the baby to term and marrying the baby's father.

``I hope they live happily ever after,'' said Phyllis Schlafly, a prominent Republican activist and the founder of the Eagle Forum.

To contact the reporter on this story: Nicholas Johnston in St. Paul, Minnesota at njohnston3@bloomberg.net

Last Updated: September 1, 2008 17:23 EDT