Dmitri S. Peskov, President Vladimir V. Putin’s spokesman, also raised concerns that President Trump was reportedly not informed about the effort, which was the subject of a New York Times report on Saturday that detailed an elaborate system of cybertools deployed by the United States inside Russia’s energy system and other targets.
The program, as described by current and former unidentified American officials, would enable an attack on the Russian power grid in the event of a major conflict between Moscow and Washington.
It was deployed, the Times reported, after years of public warnings from American security agencies about similar aggressive actions conducted by Russia. “This information means that there is a hypothetical possibility” of cyberwarfare against Russia, Mr. Peskov said.
It is unclear how deeply the so-called software implants have penetrated into the Russian power grid. Russia’s Energy Ministry said in a statement that it had received no information about attacks against its system, which is defended separately by various companies that manage it.
“The Russian energy power grid has a high level of security,” the ministry said in a statement, noting that most of the critically important facilities are connected to the state defense system. “Systemic and successful work is being carried out to use Russian technology and equipment to eliminate such risks.”
Mr. Peskov echoed that statement, but also said that “vitally important spheres of our economy have been targeted with cyberattacks from abroad.”
“We have said it many times that our relevant agencies are constantly fighting against them in order to make sure these attacks inflict no damage on our economy and sensitive spheres,” he said.
Mr. Putin has tried repeatedly “to initiate international cooperation in order to jointly counter all forms of cybercrime,” Mr. Peskov added, but the United States has not responded.
American intelligence agencies say that in fact, Russia is a major source of cybercrime and state-directed intrusion into American systems. Investigators have reported that Russian intelligence tried to gain access to American voting systems before the 2016 election, and in some cases succeeded.
Energy power grids have recently turned into an international battlefield. Mr. Trump and Congress gave new authority last year to the American military’s Cyber Command, but two administration officials told The Times that they did not think the president had been told in detail about efforts to penetrate Russia’s energy systems.
Russian foreign policy commentators said that the report about American efforts to insert software code into Russia’s energy system might jeopardize a potential Putin-Trump meeting at the G20 Summit in Japan at the end of June.
“This is a direct challenge that Moscow cannot leave unanswered,” Ruslan Pukhov, an arms expert and head of the Center for Strategies and Technologies, told Kommersant, a Russian business daily.
The two leaders might meet briefly on the sidelines of the summit, Mr. Peskov said, adding that Washington has not reached out to Moscow to organize a full-scale meeting.