Despite Mr. Trump’s public comments playing down the threat from Russia, his security officials did not hesitate in directly blaming the Russian government as the primary culprit behind the interference campaign.

“We acknowledge the threat. It is real. It is continuing,” Mr. Coats said. “We are doing everything we can to have a legitimate election that everyone can have trust in.”

Mr. Bolton said the president did raise the issue of meddling with Mr. Putin at their meeting in Helsinki, and defended what he said had been Mr. Trump’s intense focus on the issue since he took office.

“I think the president has made it abundantly clear to everybody” in the government who oversees election security. Mr. Bolton said that Mr. Trump “cares deeply about it and that he expects them to do their jobs.”

The intelligence agencies do not believe that Russian efforts to interfere in the 2018 elections have reached the same level as in the 2016 presidential campaign, Mr. Wray said. But he said the government was braced for the possibility that Russia could ramp up its efforts overnight, requiring a more forceful response from the United States.

“Any moment is just a moment before the dial can be turned up,” Mr. Wray said.

In the meantime, Mr. Wray said that the Russian efforts to inject divisive misinformation into American social media were continuing daily, even when elections are not on the horizon.

Earlier this week, Facebook reported that it had identified a political influence campaign targeting the midterm elections and had removed 32 pages and fake accounts. Facebook did not link the campaign to Russia. The company has been criticized for not having done more to detect and remove the fake accounts created by Russians during the 2016 presidential campaign.