Before doing that, the newly declassified report says, the country's nuclear arsenal must be safe from computer hackers, The Pittsburgh Tribune-Review reported Tuesday.
Without that assurance, the Defense Science Board warns, the weapons could be disabled or used on U.S. troops.
For the nuclear option to be used, a cyberattack "would have to be the kind of attack that we judge would be threatening our survival," said Paul Kaminski, chairman of the Science Board.
The report said the United States must assume that computer attacks will be part of conflicts. However, the report says the military can't be confident its computer systems would still work if attacked by an adversary with a full range of military and intelligence options.
Members of the task force, comprised of civilian experts and government advisers, said they believed the nation's enemies were planning sophisticated high-end attacks.
In a full-scale fight, the report said hackers could prevent weapons from firing or cause confusion in supply lines.
As a backup, the military should keep some weapons off the computer system so they would remain operational in the event of a cyberattack.