Chinese President Xi Jinping will pay a state visit to the United States from Sept. 22 to 25 to meet with U.S. President Barack Obama. He will also attend a series of summits to commemorate the 70th anniversary of the establishment of the United Nations from Sept. 26 to 28.

Xi and Obama's meeting will be put in the spotlight soon. But before that, let's look back to the five memorable moments when they met concerning diplomatic ties between the two countries.

Moment 1: Annenberg walk, diplomacy without neckties

Chinese President Xi Jinping meets with President Barack Obama for the second time on the morning of June 8, 2013 at The Annenberg Retreat at Sunnylands in Rancho Mirage, California. [Photo/Xinhua]

Time: June 7 - 8, 2013

Location: Annenberg Retreat, California, the United States

Memories: In June of 2013, President Xi was traveling to Latin America for a visit and then visited the United States at his leisure. He met with President Obama at the Annenberg Retreat in California in a relaxed setting. This was neither a working visit nor a state visit. So there was no welcome ceremony, no 21-gun salute, and no tie wearing.

Xi and Obama had two meetings, one private dinner and one walk together. The two leaders had personal communication and exchange for a total of 8 hours. They reached a series of important consensuses and gained positive achievements regarding the building of a new pattern of relations between two major countries of China and America, as well as bilateral cooperation and other international and regional issues.

Xi said Sino-U.S. relations were standing at a new starting point while Obama said it was a unique opportunity to take the relationship of two countries to a new level.

"Retreat meeting" became a new model for Chinese and American leaders.