US President Donald Trump slammed the United Nations on Tuesday for failing to support American-led peace efforts, but then reassured UN chief Antonio Guterres that the United States "100 percent" backs the world body. "I ended seven wars, dealt with the leaders of each and every one of these countries, and never even received a phone call from the United Nations offering to help," Trump told the 193-member General Assembly, repeating disputed claims about his role as a global peacemaker. "The United Nations wasn't there for us." Trump’s remarks reflect his long-standing wariness of multilateral institutions, particularly the United Nations. He has repeatedly questioned the effectiveness, cost and accountability of international bodies, arguing they often fail to serve US interests....