Romney had told Huntsman during an ABC debate Saturday night. "The rest of us on this stage were doing our best to get Republicans elected across the country and stop the policies of this president from being put forward."

Huntsman had a chance to respond the next morning during a debate hosted by NBC.

"I was criticized last night by governor Romney for putting my country first," Huntsman said. "And I just want to remind the people in New Hampshire and throughout the United States that he criticized me while he was out raising money for serving my country in China."

"Yes, under a Democrat like my two sons are doing in the United States Navy," the former ambassador admitted. "They're not asking what political affiliation the president is. I want to be very clear with the people here in New Hampshire and this country: I will always put my country first."

NBC debate moderator David Gregory asked Romney for a response.

"I think we serve our country first by standing for people who believe in conservative principles, and doing everything in our power to promote an agenda that does not include President Obama's agenda," Romney declared. "I just think it's most likely that the person who should represent our party running against President Obama is not someone who called him a remarkable leader and went to be his ambassador in China."

Huntsman didn't wait for Gregory to prompt him for a rebuttal.

"This nation is divided, David, because of attitudes like that," he quipped.