Former United Nations Ambassador John Bolton (R) chided GOP presidential candidate Jon Huntsman on Monday for having agreed to serve as an ambassador in the Obama administration.

Bolton, the hard-charging former diplomat for President George W. Bush who says he's now considering his own bid for the 2012 Republican nomination, rebuked Huntsman for his stint as ambassador to China.

"There is no patriotic obligation to help advance the career of a politician who is otherwise pursuing interests that are fundamentally antithetical to your values. That’s not the call of patriotism,” Bolton told National Review Online. “I don’t understand it. This is not like World War II, when we are facing an existential threat to the country as a whole, and you do put partisanship aside.”

Huntsman's time in the Obama administration has been seen as one of his biggest political liabilities as he pivots toward a campaign to unseat Obama in 2012. Many Republicans on Capitol Hill said they're unbothered by Huntsman's time as ambassador, to which he said he had agreed out of a patriotic sense of duty.

The criticism comes a day before Huntsman formally enters the race for the GOP nomination. Democrats have hammered him for allegedly shifting positions, accusing him of having "stolen a playbook from the Romney campaign," according Utah Democratic Party Chairman Wayne Holland during a Monday conference call. Holland said Huntsman would "launch a political reinvention tour the likes we have not seen" since former Massachusetts Gov. Mitt Romney's (R) hosting of the 2002 Salt Lake City Olympics.

Bolton said that he wouldn't speak in direct criticism of Huntsman, in keeping with President Reagan's famous "11th Commandment" instructing Republicans not to attack each other. But the implication of his words toward Huntsman were clear.

"I will say this, unequivocally: I would not work in Barack Obama’s administration," he told NRO.