Republican presidential candidates are lashing out at Iran, promising a pro-Israel group they will not hesitate to use America's military might against Tehran.

Former Senator Rick Santorum and former Massachusetts Governor Mitt Romney spoke to the American Israel Public Affairs Committee Tuesday, as Americans in 10 states went to the polls to vote in the Super Tuesday primaries.

Santorum called for the United States to give Iran a “clear ultimatum” to dismantle its nuclear facilities. And he said if Iran fails to comply, the U.S. should “tear them down ourselves.”

Santorum told the pro-Israel political affairs group a nuclear Iran is a “threat to freedom loving people around the world” and that if Iran gets nuclear weapons, it will serve as a shield, protecting radical regimes and terrorists around the world.

Romney accused Iran of pursuing nuclear weapons to “hold hostage the entire planet,” and said in a reference to enemies of Israel ” that placating jihadists will never result in peace.”

He said the “only thing respected by thugs and tyrants is our resolve backed our power and our readiness to use it.”

Both Santorum and Romney also accused President Barack Obama of turning his back on Israel, and chided administration officials for suggesting Iran would not use a nuclear weapon. Santorum said there is nothing in the rhetoric from Iran to suggest the country is being run by “rational actors.” Administration officials have denied the accusations saying cooperation between Israel and the U.S. in a variety of civil and military affairs has never been higher.

Fellow Republican presidential candidate Newt Gingrich is schedule to address the AIPAC conference later as he also tries to establish pro-Israel credentials with voters.