article_snippet.sent: Then-Chinese President Hu Jintao .
article_snippet.sent: German Chancellor Angela Merkel .
article_snippet.sent: Then-South Korean President Lee Myung-bak .
article_snippet.sent: British Prime Minister David Cameron .
article_snippet.sent: 2014: French President Francois Hollande .
article_snippet.sent: : Japanese Prime Minister Shinzo Abe, scheduled for April 28 . 2015: Chinese President Xi Jinping .