WASHINGTON — President Obama struck back at Russia on Thursday for its efforts to influence the 2016 election, ejecting 35 suspected Russian intelligence operatives from the United States and imposing sanctions on Russia’s two leading intelligence services.
Intelligence agencies have concluded that the G.R.U. ordered the attacks on the Democratic National Committee and other political organizations, with the approval of the Kremlin, and ultimately enabled the publication of the emails it harvested to benefit Donald J. Trump’s campaign.
The expulsion of the 35 Russians, who the administration said were spies posing as diplomats and other officials, and their families was in response to the harassment of American diplomats in Russia, State Department officials said. It was unclear if they were involved in the hacking.
In addition, the State Department announced the closing of two waterfront estates — one in Glen Cove, N.Y., and another on Maryland’s Eastern Shore — that it said were used for Russian intelligence activities, although officials declined to say whether they were specifically used in the election-related hacks.
Taken together, the sweeping actions announced by the White House, the Treasury, the State Department and intelligence agencies on Thursday amount to the strongest American response yet to a state-sponsored cyberattack. They also appeared intended to box in President-elect Trump, who will now have to decide whether to lift the sanctions on Russian intelligence agencies when he takes office next month.
Mr. Trump responded to the Russian sanctions late Thursday by reiterating a call to “move on.” But he pledged to meet with intelligence officials, who have concluded that the Russian hacking was an attempt to tip the election to Mr. Trump.
In an earlier statement from Hawaii, Mr. Obama took a subtle dig at Mr. Trump, who has consistently cast doubt on the intelligence showing that the Russian government was deeply involved in the hacking. “All Americans should be alarmed by Russia’s actions,” Mr. Obama said, and added that the United States acted after “repeated private and public warnings that we have issued to the Russian government, and are a necessary and appropriate response to efforts to harm U.S. interests in violation of established international norms of behavior.”
He issued a new executive order that allows him, and his successors, to retaliate for efforts to influence elections in the United States or those of “allies and partners,” a clear reference to concern that Russia’s next target may be Germany and France. Already there are reports of influence operations in both.
Mr. Trump’s position is at odds with most members of his party, who after classified briefings have called for investigations into the combination of cyberattacks and old-style information warfare used in the 2016 campaign. Mr. Trump has largely stuck to the theory he set forth in a debate with Hillary Clinton in September, when he said the hacks could have been organized by “somebody sitting on their bed that weighs 400 pounds.”
Russia criticized the sanctions and vowed retaliation.
“Such steps of the U.S. administration that has three weeks left to work are aimed at two things: to further harm Russian-American ties, which are at a low point as it is, as well as, obviously, deal a blow on the foreign policy plans of the incoming administration of the president-elect,” Dmitri S. Peskov, the spokesman for President Vladimir V. Putin, told reporters.
Konstantin Kosachyov, the head of the foreign affairs committee in the upper house of the Russian Parliament, told Interfax that “this is the agony not even of ‘lame ducks,’ but of ‘political corpses.’”
Despite the international fallout and political repercussions surrounding the announcement, it is not clear how much effect the sanctions will have, except on the ousted diplomats, who have until midday Sunday to leave the country. G.R.U. officials rarely travel to the United States, or keep assets here.
The four Russian intelligence officials are Igor Valentinovich Korobov, the chief of the G.R.U., and three deputies: Sergey Aleksandrovich Gizunov, Igor Olegovich Kostyukov and Vladimir Stepanovich Alexseyev.
The administration also put sanctions on three companies and organizations that it said supported the hacking operations: the Special Technology Center, a signals intelligence operation in St. Petersburg, Russia; a firm called Zorsecurity that is also known as Esage Lab; and the Autonomous Noncommercial Organization Professional Association of Designers of Data Processing Systems, whose lengthy name, American officials said, was cover for a group that provided special training for the hacking.
Still, the sanctions go well beyond the modest sanctions imposed against North Korea for its attack on Sony Pictures Entertainment two years ago, which Mr. Obama said at the time was an effort to repress free speech — a somewhat crude comedy, called “The Interview,” imagining a C.I.A. plot to assassinate Kim Jung-un, the country’s leader.
The sanctions are not as biting as previous ones in which the United States and its Western allies took aim at broad sectors of the Russian economy and blacklisted dozens of people, some of them close friends of Mr. Putin’s. Those sanctions were in response to the Russian annexation of Crimea and its activities to destabilize Ukraine. Mr. Trump suggested in an interview with The New York Times this year that he believed those sanctions were useless, and left open the possibility he might lift them.
The F.B.I. and the Department of Homeland Security on Thursday also released samples of malware and other indicators of Russian cyberactivity, including network addresses of computers commonly used by the Russians to start attacks. But the evidence in a report, in which the administration referred to the Russian cyberactivity as Grizzly Steppe, fell short of anything that would directly tie senior officers of the G.R.U. or the F.S.B., the other intelligence service, to a plan to influence the election.
A more detailed report on the intelligence, ordered by Mr. Obama, will be published in the next three weeks, though much of the information — especially evidence collected from “implants” in Russian computer systems, tapped conversations and spies — is expected to remain classified.
Several Obama administration officials, including Vice President Joseph R. Biden Jr., have suggested that there may also be a covert response, one that would be obvious to Mr. Putin but not to the public.
While that may prove satisfying, many outside experts have said that unless the public response is strong enough to impose a real cost on Mr. Putin, his government and his vast intelligence apparatus, it might not deter further activity.
“They are concerned about controlling retaliation,” said James A. Lewis, a cyberexpert at the Center for Strategic and International Studies in Washington.