"This is a very important agreement," commented James Lewis, director and senior fellow of the Strategic Technologies Program at the U.S. Center for Strategic and International Studies.

"It has the potential to end a serious source of friction between the U.S. and China. Both sides were flexible and frank," Lewis said.

The two countries also agreed to vigorously push forward negotiations and accelerate work for achieving a high-standard, mutually beneficial and win-win bilateral investment treaty (BIT).

As for the development of bilateral military-to-military relations, the two sides completed new annexes on air-to-air safety and crisis communications. At the invitation of the United States Pacific Command, the Chinese Navy will participate in the RIMPAC-2016 joint naval drills.

The two countries have also decided to designate 2016 as the China-U.S. Year of Tourism. China pledged to support a total of 50,000 Chinese and American students to study in each other's country, and welcomed the U.S. move to provide opportunities for as many as 1 million American students to learn Chinese by 2020.

People-to-people engagement

Xi chose Seattle as the first stop of his U.S. tour for its long-enjoyed robust economic links and close people-to-people ties with China.

"I have come to the United States to deepen friendship between our two peoples," Xi said in a written statement delivered at the airport upon his arrival.

A major gateway for trade with Asia and a sister city of the southwestern Chinese metropolitan of Chongqing, Seattle hosted Chinese leaders Deng Xiaoping, Jiang Zemin and Hu Jintao in the past several decades.

While visiting the Lincoln High School in the U.S. port city of Tacoma, Xi -- without a tie -- presented gifts to the students there, including books on China, a ping-pong table, and his personal invitation for the students to visit China.

He was warmly welcomed by the students from the school and also from nearby schools, who crowded the campus. He even received a football and a personalized jersey bearing his name and "No.1" on the back.

He encouraged the students to tour his country, saying "through travel, you will know China better, and hopefully you will like China."

"He is open. He talks sports with us. He is very friendly," said Alvin Johnson, a member of the school's football team.

At a welcoming dinner hosted by local governments and friendly organizations in Seattle on Sept. 22, Xi delivered a speech on China-U.S. relations which left a deep impression on many people.

"The president's speech was outstanding. He really made it very clear that it's important to have mutual respect, mutual understanding," said Dr. Constance W. Rice, a regent of the Seattle-based University of Washington.

"I was highly impressed by the speech that he made, quite inspirational I believe. And I quite enjoy that he talked about his personal life and about his background, and how he came from a poor place and lived in caves, and how he went back and wanted to bring the standard of life up for all the people in China. I thought that was really a noble thing for him to be saying," said Geoff Otterman, a senior executive of British multinational Johnson Matthey which has major operations in the United States.

Glamorous and elegant in the eyes of foreign statesmen and diplomats, China's first lady, Peng Liyuan's presence made the state visit more about the people and added color to the traditional political and economic agenda.

While the Chinese president engaged in close talks with Obama, she stayed in the public eye, participating in cultural activities.

In fact, the first lady has always valued people-to-people engagement between different cultures.

"Cultural and educational exchanges are very important to strengthening the mutual understanding and friendship between the Chinese and U.S. people and promoting the development of bilateral relations," Peng told U.S. first lady Michelle Obama during her visit in Beijing last year.

While visiting the Fred Hutchinson Cancer Research Center on Wednesday, Peng said the center' s contributions have helped many people get a chance "to live longer and better lives."

A World Health Organization goodwill ambassador for tuberculosis and HIV/AIDS, Peng called for closer China-U.S. healthcare collaboration and underlined the importance of stepping up global healthcare cooperation.

During their visits, the Chinese first couple always tried to reach out extensively to American people from all walks of life.

Although the world's top two economies have differences on some issues, they have witnessed frequent bilateral people-to-people engagement, with 43 pairs of sister provinces/states and 200 pairs of sister cities having been established. About 4.3 million mutual visits were made last year, and there is a flight between the two sides every 17 minutes.