American intelligence officials have concluded that Russia is unlikely to try to hack into voting machines or directly manipulate voting results this year. On Friday, the director of national intelligence said that state and local governments have reported attempted intrusions into their networks, but that foreign governments have not penetrated voting systems.

But Russian efforts to sway public opinion by spreading false information have continued, and officials said those efforts are becoming more refined, targeting specific groups of Americans. Almost all of the Russian disinformation efforts, according to current and former officials, are aimed at sowing dissent, polarizing the political parties and setting the stage for the 2020 presidential election.

The defense officials would not identify their targets. But other officials said some of the targets were involved in previous Russian efforts to spread disinformation in the United States and Europe, including the 2016 presidential election. The new American campaign, according to these officials, is aimed at both oligarch-funded hacking groups and Russian intelligence operatives who are part of Moscow’s disinformation campaign. It is not clear whether Cyber Command’s effort is also aimed at halting Russian operatives charged with hacking political entities.

Others said the American government must be ready to go further — cutting off the Russians’ ability to spread propaganda.

“It is very important to identify the source and essentially be able to neutralize that source,” said Laura Rosenberger, the director of the Alliance for Securing Democracy and a former Obama administration official. “These are networks that operate. The more we can identify the key nodes in those networks and remove them by taking them offline is really how we will get at this problem in a systemic way and not play Whac-a-Mole.”

Gen. Paul M. Nakasone, the head of Cyber Command and the National Security Agency, hinted at the new cyberoperations this month as he noted that American adversaries are “looking to really take us on below that level of armed conflict” by sowing distrust in society and “attempt to disrupt our elections.”

“This is what great power competition looks like today, and it’s what we will look at as we look to the future,” he said during a panel discussion in Washington.