Russia has retaliated to new US sanctions by telling Washington to cut its diplomatic staff to 455 and barring the use of some properties.
The new US embassy staffing level would be the same as at Russia's embassy in Washington.
The Russian foreign ministry also said it was seizing holiday properties and a warehouse used by US diplomats.
The new US sanctions are over Russia's 2014 annexation of Crimea and alleged interference in the US election.
They come months after the Obama administration ordered the seizure of two Russian diplomatic compounds and expelled 35 Russian diplomats in response to alleged hacking of the US Democratic Party and Hillary Clinton's campaign.
In a statement on Friday, Russia's foreign ministry said: "The US is stubbornly taking one crudely anti-Russian step after another, using the utterly fictitious pretext of Russian interference in its internal affairs."
The US expulsion of Russian diplomats "clearly violates the Vienna Convention on diplomatic relations and generally accepted diplomatic norms", it added.
It was not immediately clear how many diplomats and staff members would have to stop working at the embassy, but Russian news agencies quoted sources as saying "hundreds" of people would be affected.
Reuters news agency quoted an unnamed US embassy official as saying the embassy employed about 1,100 diplomatic and support staff in Russia, including US and Russian citizens.
Russia also said it would respond in kind if Washington decided to expel any more Russian diplomats.
Russia's move comes a day after President Vladimir Putin decried what he called "anti-Russian hysteria" in Washington.
The new US sanctions on Russia were overwhelmingly approved by both houses of Congress despite objections from the Trump White House.
US intelligence agencies believe Russia tried to sway the election in favour of Trump and now there are several investigations looking into whether anyone from his campaign helped.
Russia has always denied interfering and Mr Trump insists there was no collusion.