(Bloomberg) -- The world’s largest creditors should take coordinated and decisive action to address the “generational challenge” of poorer nations struggling with unmanageable debt burdens, a top US Treasury official said, aiming specific criticism at China, the biggest lender to emerging markets. Most Read from BloombergUS Sees Imminent Missile Strike on Israel by Iran, ProxiesVietnam Tycoon Lan Sentenced to Death Over $12 Billion FraudUS Slams Strikes on Russia Oil Refineries as Risk to Oil Ma