Carter took part in a ceremony in Xian, the provincial capital of Shaanxi, to initiate a Carter Center partnership with Xian Jiao Tong University for holding a new forum of young Chinese and Americans, with the aim of enhancing understanding between the two countries. The new forum is to be held at the Carter Center in 2015.

In Qingdao, where Carter was stationed briefly as a Marine officer not long before the founding of the People's Republic of China in 1949, Carter was amazed to find that Qingdao, then a small coastal city, has now been transformed into a modern port metropolis. He said he was deeply moved by his Chinese hosts when they presented a birthday cake to celebrate his 90th birthday with a simultaneous fireworks display on the nearby beach.

Carter met with city officials and gave speeches on the U.S.- China ties in Shanghai. In his speeches and following Q&A sessions, the former U.S. president emphasized that peace has prevailed for 35 years between the two countries.

He stressed that the U.S. and China "have had a strong diplomatic, military, and commercial involvement in this region for many generations, and that present differences are far outweighed by interests that we have in common."

"Massive trade and commerce, millions of tourists exchanged, and the 240,000 Chinese students now in the United States provide good opportunities for better understanding and mutual respect," he wrote.

Carter has often described it as his "most important life decision" to formalize the U.S. ties with China in 1979, saying it has brought about not only tremendous changes to the life of both peoples, but also peace and development in the Asian-Pacific region and the world as a whole.

He also stressed that the U.S. and China should not become enemies. "The vast Pacific Ocean has enough space for two large countries like the U.S. and China," he said, quoting Chinese President Xi Jinping.

Xi, who visited the U.S. in June 2013, is to host another summit with U.S. President Barack Obama in Beijing in early November to discuss ways of further implementing the consensus they reached last year on building a new model of major-country relationship featuring non-conflict and non-confrontation, mutual respect and win-win cooperation.