President Barack Obama took unprecedented steps Thursday to retaliate against alleged Russian interference in the 2016 election, prompting vows from Russian authorities that Moscow will respond in kind.

The administration described Russia's involvement as "Significant Malicious Cyber-Enabled Activities" and sanctioned four Russian individuals and five Russian entities for what it said was election interference.

The administration also ordered 35 Russian diplomats to leave the country and two Russian compounds are being closed.

This is the first time the names of Russian officials involved in the hacking have become public on the sanctions list.

"Russia's cyberactivities were intended to influence the election, erode faith in US democratic institutions, sow doubt about the integrity of our electoral process, and undermine confidence in the institutions of the US government," a White House statement said. "These actions are unacceptable and will not be tolerated."

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The Cold War: Then and now 01:45

According to statements from the White House and the Treasury Department, the government has sanctioned nine entities and individuals over their alleged interference in the election: the GRU and the FSB, which are two Russian intelligence services; four individual officers of the GRU; and three companies that provided material support to the GRU's operations.

The US also separately sanctioned two Russian individuals, Evgeniy Mikhailovich Bogachev and Alexey Belan, for using cyber-enabled means to allegedly cause misappropriation of funds and personal identifying information. They've long been sought by the FBI.

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The anatomy of Russia's hack of the DNC 03:05

Obama also said in the statement announcing that the diplomats have been ordered to leave the country and that those individuals and their families were given 72 hours to leave the United States.

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Obama: I told Putin to cut it out on hacking 00:59

"These actions follow repeated private and public warnings that we have issued to the Russian government, and are a necessary and appropriate response to efforts to harm US interests in violation of established international norms of behavior," Obama said in the statement.

President-elect Donald Trump -- who has publicly expressed skepticism that Russia meddled in the election -- said Thursday it's time for the US to "move on" regarding the hacking. But he added that he would meet with intelligence officials next week to be briefed on the matter.

"It's time for our country to move on to bigger and better things," Trump said in a statement. "Nevertheless, in the interest of our country and its great people, I will meet with leaders of the intelligence community next week in order to be updated on the facts of this situation."

A senior Obama administration official acknowledged to reporters Thursday that Trump could reverse the sanctions by executive order, but added, "I don't think it'd make a lot of sense."

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The Russian diplomats and the two compounds, located in Maryland and New York, were engaged in intelligence activities but were not alleged to have been involved in the hacking related to the election, White House Homeland Security adviser Lisa Monaco told reporters. The moves are instead part of the US's comprehensive reaction to election-related hacking as well as recent harassment of US personnel in Russia.

"What these individuals were doing were basically collecting intelligence. They were intelligence officers operating here and using these compounds, one in New York, one in Maryland, for intelligence collection purposes," Monaco told CNN's Jake Tapper on "The Lead" Thursday. "And what we are saying today is, in response to and in order to impose consequences for the Russian government's increasing harassment and aggression toward our personnel in Moscow, and, of course, their malicious cyberactivities, interfering and an effort to interfere in our election process, we are imposing consequences."

Russian President Vladimir Putin meets with his US counterpart Barack Obama on the sidelines of the G20 Leaders Summit in Hangzhou on September 5.

Source: CNN