According to a senior US official cybersecurity was now at the "centre of the relationship" between the US and China, with Obama having pointed out to Xi specific examples of the kind of cyber theft, in the private and public sectors, that concerned him.
According to US national security advisor Tom Donilon, Obama told Xi that if "direct theft of United States property" emanating from China continued it would be "an inhibitor to the relationship."
Donilon said that Xi "acknowledged" how important the issue was to Washington, and was clear about Obama's position on the issue.
According The Washington Post's recent reports, cyber attacks from China had accessed data from scores of Pentagon weapons programmes.
Meanwhile, Chinese officials said, following the summit, Xi was opposed to all forms of cyberspying and it "should not become the root cause of mutual suspicion and frictions between our two countries."
According to Yang Jiechi, Xi's senior foreign policy adviser, the two leaders "blazed a new trail" at the casual meeting, where formalities were dispensed with, and they "talked about cooperation and did not shy away from differences."
According to an announcement, US and China had agreed to cut hydrofluorocarbons, a potent greenhouse gas used in refrigerators and air conditioners.
HFCs, a class of greenhouse gas – are up to 1,000 times more potent than carbon dioxide, however, they clear out of the atmosphere relatively quickly, in about 10 or 15 years.
Thanks to the short lifespan cutting HFCs could deliver almost instant results, avoiding up to six times the amount of warming by 2050 as reductions in carbon dioxide.
According to the White House website the deal reached on Saturday could potentially cut the equivalent of some 90 gigatonnes of carbon dioxide by 2050, or around a year's worth of current greenhouse gas emissions.
According to commentators, though there were no signs of Chinese contrition over cyber-attacks that Washington had hoped for, the historic talks between presidents Obama and Xi Jinping lived up to their billing in respect of agreement on a host of issues ranging from climate change to North Korea.
According to Donilon, it was quite obvious now that the Chinese senior leadership understood clearly the importance of the cybertheft issue to the US.