With President Xi Jinping's state visit to the United States coming to an end, many observers are trying to fathom the strategic implications embedded in his weeklong tour of a country battling on several fronts.

Xi and US President Barack Obama reached an important agreement to jointly build a new model of major-country relationship when they met at Sunnylands in California in 2013. In a speech delivered at a banquet in Seattle on Tuesday, Xi called for advancing the new model of major-country relationship between China and the United States and working together to promote world peace and development.

Although the foundation of China and the United States to build a new type of major-country relationship is being consolidated, some observers have cast doubts over the sound development of bilateral relations.