WARSAW - U.S. Secretary of State Mike Pompeo on Thursday called for a "new era of cooperation" in resolving Middle East challenges and said no country could afford to remain on the sidelines."The United States seeks a new era of cooperation between all of our countries on how to confront these issues," Pompeo told foreign ministers and other officials from more than 60 countries in Warsaw.Pompeo refrained from directly criticizing Iran, instead including it in a list of regional challenges ranging from Syria and Yemen to Palestinian-Israeli peace."None of the region's challenges will solve themselves. We must work together for security," he said. "No country can afford to remain on the sidelines."