In the United States, the Obama administration says it has repeatedly raised concerns about cyber-theft with the Chinese.
It comes after a report by a US security company claimed a secretive Chinese military unit is behind a series of hacking attacks.
Beijing has strongly denied the claim.
“We have repeatedly raised our concerns at the highest levels about cyber-theft with senior Chinese officials including in the military and we will continue to do so. This is a very important challenge. It is one the president has been working on and urging Congress to take action on for quite some time and he will continue to do that” said White House spokesperson Jay Carney.
Unit 61398 is located in the Pudong district of Shanghai. It is alleged to have stolen data from 141 organisations from as early as 2006. Most of the targets are in the US but some are in Canada and the UK.
Mandiant is the company behind the investigation. Vice President Grady Summers said: “The evidence we provide makes it pretty clear that this is not some rogue group of hackers, they are not off on their own, they are part of PLA Unit 61398, that they are sponsored by the military and that the Communist Party of China is not only aware of their activities but actually supports their activities.”
China’s Foreign Ministry says the government firmly opposes hacking and has cast doubt on the evidence provided in the report.