U.S. Secretary of State Mike Pompeo said during a Friday night interview that he believes Russia is behind a hack that breached dozens of federal agencies and companies, including the cybersecurity company FireEye.
Speaking on the "Mark Levin Show," Pompeo said the effort was "pretty clearly" tied to Russia.
"I can't say much more as we're still unpacking precisely what it is, and I'm sure some of it will remain classified," Pompeo said. "This was a very significant effort, and I think it's the case that now we can say pretty clearly that it was the Russians that engaged in this activity."
When asked if President Donald Trump would speak out during the investigation, Pompeo said sometimes the "wiser course of action to protect the American people is to calmly go about your business and defend freedom."
FireEye, a major U.S. cybersecurity company with extensive government contracts, first revealed the hack earlier this month. In a company blog post, CEO Kevin Mandia called it “an attack by a nation with top-tier offensive capabilities.” He later said the hackers' primary goal appeared to be to steal information from the company's government clients.
Investigators with the FBI's cyber division said preliminary indications suggested whoever was responsible had "a high level of sophistication consistent with a nation-state."
Download the NBC News app for breaking news and politics
The hackers appear to have accessed computer systems by first breaking into SolarWinds, an Austin-based company that provides remote information technology services to an long list of clients around the world, including many U.S. government agencies and major corporations.
The U.S. Cybersecurity and Infrastructure Security Agency issued an emergency directive instructing federal agencies to immediately stop using the version of SolarWinds products.
The chairman of the Committee on International Affairs in the Russian Duma or parliament however, accused Pompeo of having "anti-Russian fever," in a tweet.
“Closing the U.S. Consulates General in Russia and classifying Russia as an enemy of America will not solve either internal problems or problems in bilateral relations. An aggressive policy is being unleashed not by Moscow, but by such gentlemen from Washington," he wrote.
The cyberattack began as early as March but was only discovered this month. Many of the targets were government agencies, companies that contract with governments or think tanks. Information and technology companies were also hit, according to Microsoft.
Members of the Homeland Security and Oversight Committee said on Friday that they were briefed on the matter but were left with "more questions than answers."
“After receiving a classified member briefing from the Trump Administration today on the major hack to government systems, we are left with more questions than answers," committee leaders said in a statement. "Even in the midst of an unprecedented cyberattack with far-reaching implications for our national security, Administration officials were unwilling to share the full scope of the breach and identities of the victims."
State Department officials confirmed on Friday that the last two remaining U.S. consulates in Russia, in the far eastern Russian city of Vladivostok and in Yekaterinburg just east of the Ural Mountains, will be closing. In a statement, a spokesperson said the decision was made "to optimize the work of the U.S. mission in Russia."
"The resulting realignment of personnel at U.S. Embassy Moscow will allow us to advance our foreign policy interests in Russia in the most effective and safe manner possible," the statement read in part.