Russia is considering actions to stoke protests and even violence over the U.S. election results, intelligence officials said on Tuesday, as foreign powers appear to be moving aggressively to undermine the democratic process during what is already expected to be a contentious vote count.

Russia, along with Iran and China, has already sought to influence the election through myriad efforts to spread disinformation. The officials said that new intelligence showed that Russia had created and spread a staged video falsely accusing Gov. Tim Walz of Minnesota, the Democratic vice-presidential nominee, of sexual misconduct.

The video, which was quickly debunked, is the latest in a series of false narratives that Russian operatives have fabricated this year.

With the election two weeks away, the Office of the Director of National Intelligence, along with the F.B.I. and the Cybersecurity and Infrastructure Agency, raised new warnings about the post-election period, arguing that Russia and Iran were considering stoking and amplifying domestic unrest.

The intelligence agencies said in a report that they expected “foreign actors to continue to conduct influence operations through inauguration, denigrating U.S. democracy, including by calling into question the results of the election.”

Intelligence officials first raised concerns about the post-election period in a classified document earlier this month. An unclassified version is set to be released on Tuesday. Since it was completed, new intelligence has highlighted Russia’s intentions to encourage protests and violence, especially if former President Donald J. Trump loses to Vice President Kamala Harris, the officials said.

Intelligence officials said they did not think it was likely that Russia or another country would be able interfere with the voting itself or change votes to affect the outcome without being detected, but they predicted that disruptions were likely to occur across the country on Election Day and that Russia, Iran and China would seize on the opportunity to portray democracy as chaotic and unreliable.

Malicious actors conducting ransomware attacks and other hackers could target local election offices but would have a very difficult time interfering with voting systems, which are not attached to the internet.

That said, according to intelligence officials, the period after the election, as local and state officials are certifying the vote, could be especially fraught. They cited an Iranian effort in 2020 to create a website called “Enemies of the People” that posted death threats aimed at election officials.

American intelligence agencies have concluded that Russia has sought to bolster the re-election effort of Mr. Trump and would act more aggressively after Nov. 5 if Ms. Harris wins. The agencies say that Iran has favored Ms. Harris, while China has not taken a specific stance on the presidential race, focusing its efforts on state and local races of candidates considered more favorable to China’s positions.