The U.S. Embassy in Moscow says that "all nonimmigrant visa operations" at U.S. missions across Russia will be suspended as of August 23 due to a Kremlin-imposed cap on staff at U.S. diplomatic facilities.

In an August 21 statement, the embassy said that visa operations will resume "on a greatly reduced scale" on September 1, with nonimmigrant visa interviews conducted "only in Moscow."

Visa operations at the U.S. consulates in St. Petersburg, the Ural Mountains city of Yekaterinburg, and Vladivostok on the Pacific coast will "remain suspended indefinitely," it said.

"Russia’s decision to reduce the United States' diplomatic presence here calls into question Russia's seriousness about pursuing better relations," the U.S. Embassy said.

The U.S. step is the latest development in a bitter back-and-forth between Washington and Moscow, whose relations have hit what officials on both sides say is a post-Cold War low.

Already badly strained by tension over Russia's aggression in Ukraine, its role in the war in Syria, and treatment of dissenters at home, ties were frayed further by what U.S. intelligence officials say was a concerted campaign, ordered by President Vladimir Putin and carried out through cyberattacks and propaganda, to influence the U.S. presidential election in 2016.

After Congress passed a bill imposing sanctions on Russia and making it harder for President Donald Trump to ease or lift the punitive measures, the Russian Foreign Ministry said on July 28 that Washington must reduce its diplomatic staff at the U.S. Embassy and consulates to 455 people by September 1.

Putin later said that meant the United States must cut 755 of the roughly 1,200 staff members at the missions -- many of whom are Russian.

Russian Foreign Minister Sergei Lavrov criticized the U.S. decision shortly after the announcement, claiming the move to curtail visa operations is aimed at stirring up resentment among Russians with Putin's government.

The Kremlin’s deadline for the reduction of personnel is September 1. A 2013 report by the State Department Inspector-General said that the U.S. Embassy in Moscow and the consulates in St. Petersburg, Yekaterinburg, and Vladivostok employed 1,279 staff, including 934 "locally employed" staff and 301 U.S. "direct-hire" staff.

In its August 21 statement, the U.S. Embassy said it will be able to maintain adequate staffing "to carry out essential elements of our mission."

It said the operations would remain "at reduced capacity for as long as our staffing levels are reduced" in order to comply with the Russian government’s requirement.

The embassy said that all currently scheduled nonimmigrant visa appointments in Russia were being canceled and that applicants will be provided with instructions on how to reschedule their interviews.

The embassy said that in order to comply with "international agreements, diplomatic practice, or customary international law," first priority for nonimmigrant visas must be given for the travel of UN officials, international organizations with offices in the United States, and bilateral missions.

It said priority would be given to other categories of nonimmigrant visa applications -- such as travel for medical or family emergencies -- depending on staff levels.

"This could include funerals, hospitalizations, or legal proceedings," the embassy said.

The Kremlin-ordered U.S. diplomatic staff reductions also will affect the scheduling of interviews for some immigrant visa applicants.

The U.S. Embassy said applicants for immigrant visas will be contacted if there is a change to the time and date of their interview.

For Russian university students who study in the United States, the U.S. Embassy said that it planned to offer a block of visa-interview appointments in early September.

The U.S. Embassy in Moscow and the U.S. Consulate in St. Petersburg also will no longer accept new visa applications for residents of Belarus.

Instead, the embassy says residents of Belarus are being encouraged to schedule interview appointments at the U.S. embassies in Warsaw, Kyiv, or Vilnius.

Lavrov said that change has clear political undertones.

The U.S. Embassy in Moscow and the three U.S. consulates in Russia say they will continue to provide the full range of American Citizen Services.

Those services include the issuing of passports, reports on births, assistance to victims of crime, emergency loans, and prison visits.

The U.S. Embassy statement said those services will continue because "the safety and security of American citizens overseas is one of our highest priorities."