WASHINGTON (AFP) - The United States has failed to sufficiently adapt to new cyber-security threats, exposing itself to potential terror strikes as devastating as September 11, authors of the report on the 2001 attacks warned on Wednesday.

In July 2004, the independent 9/11 commission issued a comprehensive, nearly 600-page report with numerous recommendations for upgrading the US security apparatus to avoid a new catastrophe.

A decade later the commission's former members have released a blunt follow-up, pointing out gaps in US security that increase the risk of cyber-attacks on infrastructure, including energy, transport and finance systems, and the theft of intellectual property from the private sector.

After exhaustive meetings with national security officials, "every single one of them said we're not doing what we should be doing to protect ourselves against cyber-security" threats, former 9/11 commission co-chair Tom Kean told a House homeland security panel.

"And because this stealing of information is so invisible to the American public, they don't realize what a disaster it is." The new report, released on Monday, warned that the fight against terrorism was entering a "new and dangerous phase" marked by a sense of "counterterrorism fatigue" that masked the urgency needed to address emerging threats.

"We are at September 10th levels in terms of cyber preparedness," it quoted a former senior national security leader as saying.

The former commissioners pointed to the difficulties in beefing up a security posture that brings government and the private sector into cooperation.

"The government is doing much better protecting itself and its systems than it is helping the private sector protect itself. We think our vulnerability in the latter area is greater," former commission member Jamie Gorelick said.

"We are uncomfortable with having our national security apparatus operating in the private sector," she added.

"But if you think about what the real threats are, an enemy who would shut down our power grid for example, those are real threats to which I don't believe we have great answers at the moment." For months Congress and the White House have debated cyber-security legislation that would improve information sharing about cyber threats between federal authorities and companies in strategic sectors.

But such coordination remains contentious, amid concerns about the confidentiality of personal data.