Exclusive: U.S. complains to China about North Korea's attendance at Silk Road summit

By Ben Blanchard and John RuwitchBEIJING/SHANGHAI (Reuters) - The United States warned China on Friday that North Korea's attendance at a weekend summit on China's new Silk Road could affect the participation of other countries, casting a shadow over what is Beijing's biggest diplomatic event of 2017.Two sources with knowledge of the situation said the U.S. embassy in Beijing had submitted a diplomatic note to China's foreign ministry, saying that inviting North Korea sent the wrong message at a