SIOUX FALLS, S.D. — Former U.S. Sen. Larry Pressler said Thursday that he is running for Senate as an independent.

Pressler, 71, who grew up on a farm just west of Sioux Falls near Humboldt, served two terms in the U.S. House of Representatives as a Republican from 1975 to 1979 and three Senate terms with the GOP from 1979 to 1997. He lost a 1996 re-election bid to Democrat Tim Johnson, who is not seeking re-election next year after also serving three terms.

"I'm going to say what I believe and I hope to have support across the board," Pressler said in touting positions he has taken for issues across the political spectrum.

Despite the party difference, Pressler endorsed Johnson in 2008 in his bid to hold his seat against Republican challenger Joel Dykstra. Pressler said he made the endorsement based on his childhood stuttering memories of how hard it is when you have something to say but can't easily speak out. Johnson, chairman of the Senate Banking Committee, suffered a brain hemorrhage in 2006.

Pressler also took heat when he endorsed President Barack Obama in 2008 and 2012. Pressler said he would have voted against the president's Affordable Care Act, though he believes it needs to be replaced and not just repealed. He also said he has concerns about the federal government's surveillance program and the country's continued involvement in foreign conflicts.

"I was taped during Abscam and I was offended at that level of surveillance," Pressler said of the FBI public corruption sting operation of the 1980s.

Pressler made Thursday's announcement in Sioux Falls, where he has a home, though he spends most of his time in Washington.

Pressler said that as an independent, he would have more power in Washington to end the gridlock between Democrats and Republicans. He vowed to serve only one six-year term if elected, so he could devote full-time to serving instead of raising money for the next election.

Four Republicans and one Democrat are also running for the Senate seat. Former Gov. Mike Rounds, state Sen. Larry Rhoden of Union Center, state Rep. Stace Nelson of Fulton, and Sioux Falls physician Annette Bosworth are running as Republicans. Sioux Falls businessman Rick Weiland is running as a Democrat. Libertarian Kurt Evans dropped out of the race this week.