WASHINGTON (AFP) - The United States hopes the "fast on his feet" style of China's new President Xi Jinping will loosen the stifling formality of past summits that did little to ease great power mistrust.
Mr Obama will test the proposition that China's new leader is ready to talk candidly and openly about the many differences between Washington and Beijing, at an unusual laid-back meeting on Friday and Saturday in California.
The leaders will have informal chats, a private dinner then a second day of bilateral meetings and conversations in a freewheeling agenda that is a departure for the normally tightly scripted US-China summits.
There are also plans for them to answer several questions from reporters at what will be the first summit since Xi rose to power as China's supreme leader and Obama embarked on his second White House term.
Despite simmering US-China tensions, the agenda shows Washington hopes to dispense with what aides have privately described as Obama's frustrating meetings with Mr Xi's predecessor Hu Jintao that stuck to talking points.
"(Xi) seems to be someone who is fast on his feet, who's open to engagement," said a White House official, speaking on condition of anonymity to preview the talks at the swish Annenberg retreat in sweltering Palm Springs.
Mr Xi also appears "willing to speak directly to Americans and to issues of concern to Americans in a manner that was not the hallmark of some of his predecessors," the official said.
Another White House advisor said that Mr Obama put great store in forging a personal connection with foreign leaders which could pay off down the line during a time of crisis.
"He enjoys interacting with leaders who can be at times more informal, who are direct and candid, can put aside talking points," the official said.
"We have seen indications that President Xi brings a bit more of that type of style than has been the case in the past."
Despite opening up a little on their hopes for an improved atmosphere in Sino-US summitry, White House aides are downplaying expectations of any clear progress in defusing deep differences between the two sides.
The run-up to the summit has been dominated by successive reports and allegations about alleged Chinese state-sponsored cyber espionage and hacking which has resulted in the loss of US military and commercial secrets.
The issue is at the top of the agenda on Friday - though the two sides have already announced a set of working group talks in July designed to ease expectations of a breakthrough on the issue at the first Xi-Obama summit.
Washington and Beijing are also at odds over a myriad of trade and currency disputes and China is irked by Mr Obama's military and diplomatic "rebalancing" of US power towards Asia.
The Obama administration is meanwhile concerned by an increasingly nationalistic posture by China towards territorial disputes with US allies, including in the South China Sea.
Washington also hopes that Beijing will heap more pressure on its nominal ally North Korea over its recent nuclear belligerence.
US officials say they have been encouraged by signs that Beijing has tentatively shifted towards the US position on the issue in recent weeks.