The White House on July 26 issued new guidelines on how government agencies should respond to major cyberattacks.
The announcement comes amid suspicion in the U.S. government that hackers working for Russia may have engineered the leak of e-mails stolen from the Democratic National Committee in an attempt to influence the U.S. presidential election on November 8.
White House counterterrorism adviser Lisa Monaco named Russia and China as cyber adversaries that have become more assertive.
She said Iran and North Korea also are capable and willing to carry out destructive attacks.
The guidelines include a five-point scale to grade the severity of a cyberattack.
An attack would be designated as an emergency, or level 5, if it posed an imminent threat to widescale critical infrastructure, the stability of the government, or lives of Americans.
The guidelines also offer the first public guidance on roles of federal agencies to investigate and respond to cybersecurity breaches in government and the private sector.