The US and China have agreed that they cannot accept a nuclear-armed North Korea and pledged to work closely to end Pyongyang's weapons programme, a senior US national security official has said.
Tom Donilon said the US President Barack Obama and Chinese President Xi Jinping reached "quite a bit of alignment'' on the subject of curbing North Korea's ambitions during a meeting on Saturday.
"They agreed that North Korea has to denuclearise, that neither country will accept North Korea as a nuclear-armed state and that we would work together to deepen co-operation and dialogue to achieve denuclearisation," he said on Saturday, at the end of two days of meeting between Obama and Xi at an estate in the California desert.
China is Pyongyang's ally but has become increasingly concerned at North Korean threats of war against South Korea.
Chinese State Councillor Yang Jiechi told a separate news conference that Xi had told Obama that China and the United States were "the same in their positions and objectives" on the North Korean nuclear issue.
Obama and Xi had wide-ranging talks, including a 50-minute discussion outdoors, to conclude a get-to-know-you visit that included an extensive discussion of how to rein in North Korea, whose rhetoric in recent months has rattled the Asia-Pacific as well as the US.
Cybersecurity should not become the root cause of mutual suspicion and friction, rather it should be a new bright spot in
Donilon gave no specifics but said the US president also described for China's leader the types of problems the US has faced from cyber intrusions and theft of intellectual property.
According to Donilon, the president underscored for Xi that the US has no doubt that the intrusions are coming from inside China, and said that Obama told the Chinese leader if the issue were not addressed, it would become a "very difficult problem in the economic relationship".
Donilon said Obama requested that the Chinese government "engage" on the issue and also understand that that type of activity is inconsistent with the kind of relationship the US desires to build with China.
Obama's national security adviser told reporters that China now understood the depth of US worries about the problem.
Yang, briefing Chinese reporters, said Beijing wanted co-operation rather than friction with the US over cybersecurity.
"Cybersecurity should not become the root cause of mutual suspicion and friction, rather it should be a new bright spot in our co-operation," Yang said.