While pointing out "it's still primary season for the Republican Party," Obama said Monday, "It's worth noting that I first arrived on the national stage with a speech at the Democratic convention that was entirely about American exceptionalism and that my entire career has been a testimony to American exceptionalism."
Obama was asked about Romney's comment during a weekend speech in Wisconsin that "Our president doesn't have the same feelings about American exceptionalism that we do, and I think over the last three or four years, some people around the world have begun to question that."
"I will cut folks some slack for now, because they're still trying to get their nomination," Obama said during a news conference in Washington with two more-conservative world leaders, Mexican President Felipe Calderon and Canadian Prime Minister Stephen Harper.
While Harper and Calderon declined to comment on U.S. influence globally, Harper praised Obama and the United States for its leadership under his presidency.
"For Canada, the United States is and always will be our closest neighbor, our greatest ally and our best friend," Harper said. "And I believe that American leadership is at all times great and indispensable for the world."
Harper said the countries have done "great things together" in responding through the Group of 20 and bilaterally on the economic recession and recovery.
"We had, under your leadership, Barack, that successful intervention in Libya," the Canadian prime minister said through an interpreter. "Our trade relationship is the biggest in the world and growing, and so I think it's been a tremendous partnership."
Wisconsin, Maryland and the District of Columbia conduct primaries Tuesday.