He took a detour from his presidential campaign and went to Ottawa to address the Economic Club of Canada.

"There aren't any votes to be won up here," he told the audience before setting out on a speech outlining the importance of Canada and U.S. relations, particularly in the economic sphere.

Although he did not refer directly to his presidential rival Barack Obama, McCain alluded to the Democrat's criticism of NAFTA.

"Demanding unilateral changes and threatening to abrogate an agreement that has increased trade and prosperity is nothing more than retreating behind protectionist walls," he said.

McCain said if he is elected president, he will respect international agreements. Obama criticized the economic pact during his Democratic primary battles with vanquished leadership contender Hillary Clinton. Both the presumptive presidential nominee and the former first lady campaigned promising they would seek changes in the pact. More...