Alaska Gov. Sarah Palin announced Friday she will resign from office effective July 26th. The former Republican vice presidential candidate did not elaborate on her decision or say what her future plans are.

Palin said she planned to make a "positive change outside government," without elaborating. She also expressed frustration with her current role as governor.

"I cannot stand here as your governor and allow the millions of dollars and all that time go to waste just so I can hold the title of governor."

Later, on Twitter, she promised supporters more details. "We'll soon attach info on decision to not seek re-election ... this is in Alaska's best interest, my family's happy ... it is good. Stay tuned."

"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," Palin said in a statement released by her office.

"It is my duty to always protect our great state. With that in mind, my family and I determined that it is best to make a difference this summer and I am willing to change things, so that this administration, with its positive agenda, its accomplishments and its successful road to an incredible future can continue without interruption and with great administrative and legislative success."

The announcement stirred speculation that she would focus on a 2012 bid for the Republican nomination for president. Her term would have ended in 2010.

Lt. Gov. Sean Parnell will replace Palin, whose decision took Parnell by surprise. He said he was told on Wednesday evening and was not aware that any presidential ambitions were behind the move.

Palin was first elected in 2006 on a populist platform, but her popularity has waned as she waged in partisan politics following her return from the 2008 presidential campaign.

She emerged from relative obscurity nearly a year ago when she was tapped as then Republican presidential candidate John McCain's running mate. She made a campaign stop in Omaha last October.

Palin's family and the ridicule they endure being in the public eye was part of her decision. She complained that her 14-month-old son, Trig, who was diagnosed with Down's syndrome, had been "mocked and ridiculed by some mean-spirited adults recently." She didn't elaborate.

Palin's delivery of two weeks' notice rattles a Republican Party plagued with setbacks in recent weeks, including extramarital affairs disclosed by two other 2012 presidential prospects, Nevada Sen. John Ensign and South Carolina Gov. Mark Sanford.