The United States has backed away from its contentious demands for lucrative procurement projects in the renegotiation of the North American free-trade agreement, The Canadian Press has learned.Mexico and Canada are both quietly taking credit for standing firm against the controversial U.S. position that would have effectively limited their respective countries’ ability to bid on valuable American government infrastructure projects.Multiple sources, speaking on the condition of anonymity, cited the competing claims as one example of the animosity between Canada and Mexico that has arisen since Mexico reached its own NAFTA deal with . . .