Enhancing relations, increasing trust and transparency, and developing a strong mechanism to manage differences are all important for the construction of a new model for relations between major countries, Donilon said.

"Xi will stop in California after formal visits to Trinidad and Tobago and Mexico, where he will be accompanied by a large group of senior officials," AP reported. "If that entourage descends in full on the Sunnylands estate, US diplomats said the White House might feel the need to bring similarly large numbers."

Shi Yinhong, an expert on US studies at Beijing-based Renmin University of China, said the most important message China wants Donilon to take back is that it really hopes to build a new type of big-power relationship, and both sides should respect each other's core interests.

Shi said the meeting of Xi and Obama will play an important role in future ties.

The talks will cover pressing issues including the Korean Peninsula, Iran, Japan and cybersecurity, Shi said.

Kenneth Lieberthal, a senior fellow at The Brookings Institution and former senior director for Asia at the National Security Council, said a new type of major power relations is "an ambitious and important goal".

"To be meaningful, it requires that the two governments work out new initiatives that they can take to solidify the bases for long-term cooperation on both bilateral and multilateral issues," he said.

"A key necessity is that President Obama and President Xi develop substantial mutual understanding and personal trust," he said. "It is significant, therefore, that they are seizing the first opportunity to meet together for an extended discussion."

Richard Bush, senior fellow at the Brookings Institution, said the purpose of the meeting is not to bargain or to solve specific problems, but to set a tone and create a sense of shared fate between the two leaders.

"Two days in California allow both more time and an informal environment for each to talk about his domestic challenges and visions for the future, about his country's role in the international system and how US-China relations fits with all of this."

Such an interchange is particularly important because each president sits atop a complex governmental system that is not easy to monitor, Bush said, adding that this is one of the reasons for recent friction between the two countries.