Qa'dah 4, 1435, Aug 30, 2014, SPA -- President Barack Obama and Canadian Prime Minister Stephen Harper talked by telephone on Saturday to discuss next week's NATO summit in Wales and the situation in Iraq, Reuters quoted the White House as saying. "Both leaders agreed on the importance of ensuring Alliance unity on measures to strengthen NATO's readiness and responsiveness to the full range of current and future threats," the White House said in a statement. Obama stressed that agreeing on increased defense investment in all areas would be a top priority at the NATO summit, it added.