For the first time, the US has publicly accused China and Russia of stealing cutting-edge American high-tech information to build their own economies.
"The nations of China and Russia, through their intelligence services and through their corporations, are attacking our research and development.
That's a serious issue, because if we build their economies on our information, I don't think that is right," the National Counterintelligence executive Bryant said while unveiling a report in Washington on Thursday.
Bryant's office is responsible for mounting an integrated national counterintelligence battle against foreign intelligence threats to the United States.
"US private sector firms and cybersecurity specialists have reported an onslaught of computer network intrusions that have originated in China," the CNN quoted the report as saying.
In a statement, Rogers said the report 'once again underscores the need for America's allies across Asia and Europe to join forces to pressure Beijing to end this illegal behaviour.'
The report is the most forceful public airing of US allegations after years of private complaints to Beijing and Moscow, US media reports said.
It noted that analysts could not pinpoint specific responsibility for many of the intrusions, but Bryant said the source of the attacks could be government intelligence services, corporations or individuals.
The latest intelligence community assessment comes on the heels of House Intelligence Committee Chairman Mike Rogers' harsh criticism of what he referred to as China's 'predatory campaign' of stealing US intellectual property.
Last month, Rogers said the cyber attacks against the United States had reached 'an intolerable level' and were harming American national security.
Bryant said American companies and the US government produce approximately $400 billion of research and development each year. Depending on whose figures you go by, the losses each year range from $2 billion to as much as $400 billion -- estimates that Bryant called 'meaningless.'
The report gives the example of the Valspar Corporation, where an employee downloaded proprietary paint formulas that he planned to take to a job in China.
The theft was valued at $20 million, representing one-eighth of Valspar's annual profit, the CNN report said.