(CNN) 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."

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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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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"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."

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.

Russia's reaction

Russia swiftly responded to the actions Thursday. Russia will respond to any "hostile steps" that the US may take in response to allegations of hacking during the 2016 election, according to the official representative for the ministry.

Russian Foreign Ministry spokeswoman Maria Zakharova said similar steps will be taken in response to the expulsions, though she did not immediately provide further details. Dmitri Peskov, a spokesman for Russian President Vladimir Putin, told reporters there is "no alternative to reciprocal measures," adding that Putin is "in no rush to make a decision."

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Russia's first visible action came later Thursday, when Russian authorities ordered the closure of the Anglo-American School of Moscow, a US official briefed on the matter said. The order from the Russian government closes the school, which serves children of US, British and Canadian embassy personnel, to US and foreign nationals.

The order also closes access to the US embassy vacation house in Serebryany Bor, near Moscow.

Soon after the administration's announcement, Russia's embassy in the UK tweeted that Obama's actions were "Cold War deja vu" and described the administration as "hapless."

President Obama expels 35 🇷🇺 diplomats in Cold War deja vu. As everybody, incl 🇺🇸 people, will be glad to see the last of this hapless Adm. pic.twitter.com/mleqA16H8D — Russian Embassy, UK (@RussianEmbassy) December 29, 2016

Congressional Republicans split with Trump

House Speaker Paul Ryan, a Republican, called the sanctions "overdue," adding that it is an "appropriate way to end eight years of failed policy with Russia."

"Russia does not share America's interests," he said in a statement Thursday. "In fact, it has consistently sought to undermine them, sowing dangerous instability around the world. While today's action by the administration is overdue, it is an appropriate way to end eight years of failed policy with Russia. And it serves as a prime example of this administration's ineffective foreign policy that has left America weaker in the eyes of the world."

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Republican Sens. John McCain and Lindsey Graham, two of Russia's fiercest critics in the US Senate, called for stronger sanctions against Russia.

"The retaliatory measures announced by the Obama administration today are long overdue. But ultimately, they are a small price for Russia to pay for its brazen attack on American democracy. We intend to lead the effort in the new Congress to impose stronger sanctions on Russia," the two said in a joint statement.

Director of National Intelligence James Clapper issued a statement on Thursday reiterating the agency's confidence that the Russian government was involved in the US hacking.

"This activity by Russian intelligence services is part of a decade-long campaign of cyber-enabled operations directed at the US Government and its citizens," the statement read. "The US Government can confirm that the Russian government, including Russia's civilian and military intelligence services, conducted many of the activities generally described by a number of these security companies."

Months of internal debate

The administration's announcement comes after months of internal debate over how to respond to Russian hacking that US law enforcement and intelligence agencies have watched take place for over a year.

The US government announced in October that it was "confident" that the Russian government orchestrated the hacking of the Democratic National Committee and other political organizations of the Democratic Party to influence the 2016 election.

Those hacks resulted in the public release of thousands of stolen emails, many of which included damaging revelations about the Democratic Party and former Secretary of State Hillary Clinton, the party's nominee.

The hacking of DNC emails eventually led to the resignation of former chairwoman Debbie Wasserman Schultz after emails showed her favoring Clinton over Vermont Sen. Bernie Sanders during the Democratic primary.