MANCHESTER, N.H. —  Republican Mitt Romney said Thursday he would be willing to use a military blockade or "bombardment of some kind" to prevent Iran from gaining a nuclear weapon.

The former Massachusetts governor's comments came as the Bush administration announced new sanctions designed to isolate the government in Tehran. Romney applauded the move, while several Democratic presidential contenders spoke out against it -- and used it as an opportunity to criticize front-runner Hillary Rodham Clinton.

Said former North Carolina Sen. John Edwards: "I learned a clear lesson from the lead-up to the Iraq War in 2002: If you give this president an inch, he will take a mile and launch a war. Senator Clinton apparently learned a different lesson."

Clinton voted last month for legislation sponsored by Sens. Joe Lieberman and Jon Kyl designating Iran's Revolutionary Guard a terrorist organization, the only Democratic senator running for president who did so. Edwards and other critics say the measure could pave the way toward American military action there.

In a statement Thursday, presidential rival Chris Dodd echoed Edwards' argument.

"The aggressive actions taken today by the administration absent any corresponding diplomatic action is exactly what we all should have known was coming when we considered our vote on the Kyl-Lieberman Amendment, and smacks, frankly, of a dangerous step toward armed confrontation with Iran," Dodd said.

Romney, who has been advocating a hard line against Iran throughout his presidential campaign, said military action would be necessary if severe economic and diplomatic sanctions don't convince Iranian leaders to abandon pursuit of a nuclear weapon.

The Iranian government contends its program is aimed toward providing nuclear power.

"If for some reasons they continue down their course of folly toward nuclear ambition, then I would take military action if that's available to us," Romney told a crowd of doctors and nurses during a question period that followed a health care speech.

He added: "That's an option that's on the table. And it's is not something which we'll spell out specifically. I really can't lay out exactly how that would be done, but we have a number of options from blockade to bombardment of some kind. And that's something we very much have to keep on the table, and we will ready ourselves to be able to take, because, frankly, I think it's unacceptable for Iran to have nuclear weapons."

Last year, while still governor, Romney refused to provide a security escort or any state services in support of former Iranian President Mohammad Khatami, who visited Massachusetts to speak at Harvard University.

In January, Romney traveled to a security conference in Israel, where he called for economic sanctions against Iran similar to those against South Africa during its apartheid period.

Subsequently, he has called for indicting Iranian President Mahmoud Ahmadinejad for saying "Israel's Zionist regime should be wiped off the map." Romney suggested using the U.N.'s Genocide Convention against the leader on charges of inciting genocide.

In September, he also chastised Columbia University for allowing Ahmadinejad to speak on its campus, and railed against the Iranian leader after he asked to visit ground zero.