WASHINGTON – Former Minnesota governor Tim Pawlenty, a Republican, announced Monday he was formally exploring a 2012 challenge to President Barack Obama.

"We have a great country, but we're headed in the wrong direction. We need a real debate with President Obama, so the American people can decide how to get this country back on track," Pawlenty said in a statement.

Pawlenty, long rumored to be seeking the presidency but largely unknown outside his home state, announced his plans to create a presidential exploratory committee, generally a must-do step that allows potential candidates help to gauge the potential for raising the vast sums of money required.

His announcement came as other potential Republican candidates, including former governors Mitt Romney and Sarah Palin, had yet to say formally one way or the other whether they will seek the White House.

Republican officials worry that the crowded field of possible White House hopefuls could end up helping Obama, who is sure to get his party's 2012 nod but is seen as vulnerable amid stubbornly high US unemployment.

"I will unite the Republican Party around my optimistic vision. We need to make the tough decisions to reform and renew the American dream. I am looking forward to making my case," vowed Pawlenty.

Pawlenty, 50, lives in Minnesota with his wife Mary and two teenage daughters.