President Obama held a two-day summit with his Chinese counterpart, Xi Jinping, where the pair discussed issues including cybersecurity and the North Korean nuclear threat. White House national security adviser Tom Donilon told reporters that Obama raised the subject of hacking and industrial espionage from Chinese sources, and warned Xi that such activity could become a "very difficult problem" and an 'inhibitor' to the relationship between the two countries.

Obama calls progress "terrific"

Donilon did not provide specific details of the conversation, nor any indication of Xi's response. Obama is said to have made it clear to his opposite number that he believes China to be the origin of cyberattacks against US targets, and called the pair's progress "terrific."

The summit was the first meeting between the two presidents since Xi came to power in March, and could set the tone for discourse between the US and China in the next few years. "Cybersecurity should not become the root cause of mutual suspicion and friction, said Chinese State Councillor Yang Jiechi, "rather it should be a new bright spot in our cooperation." The comments were made during a separate media briefing for Chinese reporters.

On North Korea, Yang said that the US and China were "the same in their positions and objectives," with both agreeing that the reclusive state must begin the process of denuclearization. Donilon said the leaders reached "quite a bit of alignment" on the issue. North Korea conducted its third test of a nuclear weapon in February.

China and the US have agreed to hold high-level talks on the cybersecurity issue as part of next month's Strategic and Economic Dialogue meeting. This week it emerged that Chinese hackers stole confidential documents from both the Democrat and Republican 2008 presidential campaigns.