As he winds down his tenure at the helm of the Pentagon, Defense Secretary Leon Panetta is warning that cyber-attacks constitute one of the “great threats” facing the United States and urged Congress to advance legislation to address the danger.

“Cyber is now at a point where the technology is there to cripple a country, to take down our power grid system, to take down our government system, take down our financial system and literally paralyze the country,” Panetta said. “That is the reality.  And so, for that reason, it is extremely important that we do everything possible to develop the technical capabilities to operate effectively in cyberspace.”

Panetta, who plans to retire, addressed a gathering at Georgetown University recently in one of his final public appearances as defense chief. President Barack Obama has named former Republican senator Chuck Hagel as Panetta’s successor, a nomination that is currently pending before the Senate.

As he prepares to leave office, Panetta said the perils of cyber-attacks posed by would-be adversaries are among his biggest worries.

“There is no question in my mind that part and parcel of any attack on this country in the future by any enemy is going to include a cyber element to it–that that’s going to be part of the weapon that will be used to cripple us in the event of an attack,” he said, adding that the United States encounters thousands of cyber-attacks daily.

The Pentagon has “invested a great deal” in countering cyber threats over the last two years but more needs to be done in terms of investments and working closely with the private sector to protect key aspects of the economy and infrastructure, Panetta said.

“We’re going to invest more in cyber, to try to give us the capability to be able to protect our critical infrastructure against the kind of imminent and destructive cyber-attacks that I just talked about,” he said. “But to do that, frankly, we’re going to need legislation.”

“We’ve asked for legislation from the Congress to try to give us the tools we need–the legal tools we need so that we can develop a partnership with the private sector to be able to confront these challenges,” he added. 

Attempts last year to pass legislation in Congress stalled, with Republicans blocking a bill in the Senate they believed would overly regulate businesses. A separate bill passed by the House of Representatives did not make it through the Senate.

Seeking to rekindle the effort, seven Democratic senators introduced a new bill in January that calls for “enhancing the security and resiliency of public and private communications and information networks against cyber-attacks.” The five-page Cyber Security and American Competiveness Act of 2013 offered few specifics, as detailed language is expected to arise in subsequent measures later this year.

The Pentagon, in the meantime, is reportedly moving forward with boosting its defensive and offensive cyber capabilities. The Washington Post reported last month that senior Pentagon officials have signed off on a plan to expand its cyber-security force by five times the current level over the next several years. It would increase Cyber Command personnel from 900 to 4,900 troops and civilians, the Post reported.

The plan would also establish the creation of three missions under Cyber Command. One would be to protect computer systems vital to electrical grids, power plants and other infrastructure critical for national and economic, a second to help commanders plan and execute cyber-attacks, and a third to guard the Pentagon’s networks, according to the report.