Cybersecurity and Infrastructure Security Agency

The action, the first of several planned steps by the federal government, follows the ransomware hack of the Colonial Pipeline.

The agency said the U.S. system was prepared to handle the process of questioning the outcome of an election.

A bulletin from the FBI and Cybersecurity and Infrastructure Security Agency describes a broad ongoing attempt to compromise American networks, including "some risk" to elections information.

Cybersecurity experts say the origin of the messages remains unknown and may be the product of a foreign disinformation effort.

Senate Majority Leader Mitch McConnell and others rebuked President Trump's equivocation about whether he might transfer power peacefully against a backdrop of uncertainty about the ongoing election.