PHOENIX -- Arizona Gov. Jan Brewer on Thursday announced her candidacy for a full term in next year's elections, saying she will be the strong leader the state needs to tackle its budget crisis.

Some of the spending cuts being imposed to close the state's budget shortfalls weren't easy, Brewer said in remarks prepared a news conference to announce her candidacy.

"But tough times call for a tough leader," she said. "We have made tough choices while making sure that we are offering education, public safety and other services to those who need them most."

She also pledged to take on all of the big challenges -- ranging from health care to transportation.

Brewer earlier Thursday filed organizational paperwork to launch her campaign.

The former lawmaker and former county supervisor was Arizona's elected secretary of state when she became governor in January when Democrat Janet Napolitano resigned to take the top spot at the U.S. Department of Homeland Security.

Brewer's prepared remarks didn't mention her still-pending proposal for a temporary sales tax increase to help close budget shortfalls that she blamed, as she has since taking office, on "years of overspending and living beyond our dreams."

But she said that tax reform -- an apparent reference to her calls for long-term tax relief for businesses -- would help create a business climate to attract high-wage jobs and investment.

As a candidate, Brewer has the advantage of being an incumbent known to many Arizona voters. However, she will be running at a time when she and other leaders are making politically difficult decisions on how to solve Arizona's budget crisis.

Fellow Republicans had hailed her replacement of Napolitano but she angered many GOP legislators last spring by proposing a temporary sales tax increase to help close solve budget shortfalls in the budgets for the current and next two fiscal years.

As an unelected incumbent, Brewer could be vulnerable both within her own party and in the general election, largely on the budget issue, said Patrick Kenney, Arizona State University political science chairman. "That's trouble."

Brewer has been unable to post big successes on the budget although Republicans also control the Legislature, and her efforts to blame budget troubles on Napolitano will be increasingly harder as more budget cuts are made on her watch, Kenney said.

Announced candidates for the 2010 Republican nomination include Tucson attorney John Munger, a former state Republican Party chairman. Paradise Valley Mayor Vernon Parker is formally exploring whether to enter the race, and State Treasurer Dean Martin also has expressed interest.

Attorney General Terry Goddard is regarded as the likely Democratic nominee. He has said he intends to run but has not formally announced.

State Democratic Party Chairman Don Bivens said Brewer has failed to provide needed leadership during the budget crisis and faces having to run on a record of "job losses, education cuts and Capitol gridlock."

From within her own party, Martin said Brewer's unelected status and her performance on the budget leave the race wide open. "We need to get this budget fixed before we start talking about contract extensions," he said.