The Russian government has indicated they will expel the same number of diplomats from the nations that have expelled Russian diplomats over the poisoning of an ex-Russian spy in Britain.
U.S. Ambassador Jon Huntsman was summoned to the Foreign Ministry earlier today where he was given notice Russia is responding quid pro quo to the U.S. decision to expel 60 Russian diplomats. The first representative facility to be closed is the US Consulate General in St. Petersburg.
American citizens traveling to or currently in Russia need to pay particular attention to this developing situation. Russia is a vast country spanning 11 time zones and there is strong potential for the closure of additional facilities.
The remaining U.S. diplomatic facilities in Russia offering the normal array of U.S. citizen services are Moscow (embassy), Yekaterinburg (central) and Vladivostok (far East).
More information on diplomatic facilities can be found on the embassy website:
https://ru.usembassy.gov/embassy-consulates/