Alaska Gov. Sarah Palin announced Friday she will resign as governor by the end of July and will not seek a second term in 2010.

Palin, Republican Arizona Sen. John McCain's vice presidential running mate last year, said Lt. Gov. Sean Parnell would be sworn in as the new governor July 25.

Speaking outside her home in Wasilla, Alaska, Palin said being a "lame-duck" governor would have been the "easiest path" as she approaches her final year in office.

"Once I decided not to run for re-election, I also felt that to embrace the conventional 'lame-duck' status in this particular climate would just be another dose of 'politics as usual,' something I campaigned against and will always oppose," she said.

"People who know me know that besides faith and family, nothing's more important to me than our beloved Alaska," Palin said. "It is my duty to always protect our great state."

She said the new governor's administration would build on the accomplishments of hers.

"I look forward to helping others -- to fight for our state and our country and campaign for those who believe in smaller government, free enterprise, strong national security, support for our troops and energy independence," she said.