Russia's Washington chancery annex is seen, Thursday, Aug. 31, 2017 in Washington.  In an escalating tit-for-tat, the United States forced Russia on Thursday to shutter its consulate in San Francisco and scale back its diplomatic presence in Washington and New York, as relations between the two former Cold War foes continued to unravel. (AP Photo/Jacquelyn Martin)
Russia's Washington chancery annex is seen, Thursday, Aug. 31, 2017 in Washington. In an escalating tit-for-tat, the United States forced Russia on Thursday to shutter its consulate in San Francisco and scale back its diplomatic presence in Washington and New York, as relations between the two former Cold War foes continued to unravel. (AP Photo/Jacquelyn Martin) Credit: Jacquelyn Martin

Washington — Escalating a diplomatic tit-for-tat, the United States abruptly ordered Russia on Thursday to shutter its San Francisco consulate and close offices in Washington and New York, intensifying tensions between the former Cold War foes. Washington gave Moscow 48 hours to comply.

The Trump administration described its action as retaliation for the Kremlin’s “unwarranted and detrimental” demand earlier this month that the U.S. cut its diplomatic staff in Russia. But Moscow declared it a major escalation, with a top Russian lawmaker saying the move heralded “the hot phase of diplomatic war.”

“The United States is prepared to take further action as necessary and as warranted,” State Department spokeswoman Heather Nauert said. Still, she said the U.S. hoped both countries could now move toward “improved relations” and “increased cooperation.”

It was a harsh welcome to Washington for new Russian Ambassador Anatoly Antonov, who arrived only hours after the U.S. announcement. At the airport, Antonov cited a maxim of former Soviet leader Vladimir Lenin as he urged caution and professionalism.

“We don’t need hysterical impulses,” Russian news agencies quoted Antonov as saying.

The closings on both U.S. coasts marked perhaps the most drastic diplomatic measure by the United States against Russia since 1986, near the end of the Cold War, when the nuclear-armed powers expelled dozens of each other’s diplomats.

And it comes amid some of the broadest strains in their relationship ever since. The two countries have clashed over the wars in Ukraine and Syria, but most significantly over American allegations that Russia meddled in the 2016 U.S. election to boost President Donald Trump’s chances of victory. Investigations continue into whether Trump’s campaign colluded with Moscow.

By Saturday, the Russians must close their consulate in San Francisco and an official residence there. Though Russia can keep its New York consulate and Washington embassy, trade missions housed in satellite offices in both of those cities must shut down, a senior Trump administration official said. The official briefed reporters on a conference call on condition of anonymity.

Outside the consulate building high atop a hill overlooking the San Francisco Bay, there were no visible signs of an exodus on Thursday. Consular officials walked in and out of the stately building, and Russian citizens who had scheduled appointments said they were able to pick up or renew their passports.

“It’s sad, because I’ve lived many years in the U.S. and there are strong ties between the countries,” said Kate Stanton, a San Francisco real estate agent who said she holds dual U.S.-Russian citizenship.

American counterintelligence officials have long kept a watchful eye on Russia’s outpost in San Francisco, concerned that people posted to the consulate as diplomats were engaged in espionage. The U.S. late last year kicked out several Russians who posted there, calling it a response to election interference.

The U.S. isn’t expelling any Russian officials this time.

Those who work at the shuttered offices can be reassigned elsewhere in the United States, the senior official said.