Republican Mitt Romney on Wednesday jabbed at President Bush, saying the image of the United States has suffered globally based on the perception that it invaded Iraq unilaterally.

Addressing civic and business leaders, the former Massachusetts governor chided Bush as his fellow Republican traveled overseas for an economic summit and a meeting with Russian President Vladimir Putin, who has been critical of U.S. efforts to install a missile defense shield in Europe.

"I do think that we have suffered over the past several years for a number of reasons, and I think you probably know what they are," Romney said, citing the absence of strong international support in the lead-up to the war.

"There has been the perception that we have not been as open and participative with other nations as is our normal approach," he said.

The anti-Bush comments revived a theme from the debate Tuesday night in which Romney and several of his GOP rivals criticized the president on his management of the war, the immigration bill and diplomacy.

"There are a few countries and a few people who have demonstrated themselves for being so evil that we will cut off our engagement with those countries," Romney said, mentioning Cuba and Iran. "With most of the others, even those that are doing authoritative and outrageous acts like Putin in Russia, I don't want to cut off talking."

He said the next president must not only re-engage Middle East and European leaders — labeling France's new conservative leader Nicolas Sarkozy as a potential "blood brother" — but also Latin American nations.

Romney said his call for expanding the U.S. prison camp for terrorists at Guantanamo Bay, Cuba, was consistent with that world view, despite condemnation from some human rights groups and other countries. He said the prison's intense interrogating environment is necessary to prevent future attacks.

"I think some people see Guantanamo as a source of America's arrogance, and I see it as a source of America's resolve," Romney said.

He said terrorists such as Sept. 11 mastermind Khalid Sheik Mohammed had broken when they were kept from the traditional U.S. justice system with legal representation and typical court proceedings.

Romney added: "The food down there is unbelievable. This is not this gulag; this is a modern prison which treats people with dignity and respect."

In a follow-up news conference, Romney repeated his criticism of an immigration compromise brokered by one of his rivals, Sen. John McCain, R-Ariz. Romney said the bill, as currently drafted, would allow illegal immigrants to remain in the country indefinitely.

Asked how he would eliminate that group, estimated at 12 million, without a roundup, Romney said there were two alternatives: make a registration visa proposed in McCain's bill temporary instead of permanent, or wait for attrition created by efforts to secure U.S. borders and new efforts to force employers to verify the legality of their workers.

"No loss of workers necessary," the former governor said. "The idea is a gradual and humane replacement of illegal workers with either U.S. citizens or legal immigrants."