Cybersecurity has become crucial to homeland security, according to the US Department of Homeland Security.
In its first four-yearly review, the Department of Homeland Security said safeguarding and securing cyberspace had become one of the homeland security community's most important missions.
"Our vision is a cyberspace that supports a secure and resilient infrastructure, that enables innovation and prosperity, and that protects privacy and other civil liberties by design," it said.
"It is one in which we can use cyberspace with confidence to advance our economic interests and maintain national security under all conditions."
The Department of Homeland Security said cyberspace is inherently insecure, but that the US faced "a variety of adversaries" bent on using US dependence on cyberspace against it.
"Sophisticated cybercriminals and nation-states, among others, are among [those] who now pose great cost and risk both to our economy and national security," it said.
"They exploit vulnerabilities in cyberspace to steal money and information, and to destroy, disrupt, or threaten the delivery of critical services."
The review comes just after it emerged that Google and at least 30 other leading US corporations were targeted by hackers based in China.
The Chinese government denied it was behind the attacks, and accused the US of spying on China via the internet.
In the UK, a leaked MI5 letter repeated warnings from 2007 that Chinese spies were targeting UK businesses and staff with a wide variety of attacks, including sexual inducements, blackmail and gifts of USB memory sticks that contain malware, to reveal company secrets.