A top US diplomat on Wednesday pressed Europe to slap new sanctions on Iran over its nuclear program, stepping up a push by Washington to hold Teheran accountable for defying UN demands. A week after the United States announced new sanctions against Iran, Undersecretary of State Nicholas Burns met with French officials to press for other Western allies to follow suit, or at least cool down their economic ties with the Islamic republic. Burns said military action against Iran was "not inevitable, and not desirable," and suggested that tougher penalties would be a way to avoid it. "If we want diplomacy to succeed, we're going to have to see more tough-minded diplomacy," he told reporters. "We are going to have to see additional efforts by Europe to support diplomacy through sanctions."