Chinese President Xi Jinping (R) is welcomed by U.S. President Barack Obama (L) at the South Lawn of the White House in Washington D.C., the United States, Sept. 25, 2015. Xi arrived in Washington, the second stop of his first state visit to the United States, on Thursday after a busy two-and-a-half-day stay in West Coast hub Seattle. (Xinhua/Pang Xinglei)