US forces closure of Russia’s San Francisco consulate, 2 other diplomatic properties

A State Department spokesperson warned that the U.S. could have gone further.

The U.S. embassy and consulates' employees are largely Russian nationals, and there were reports that some 600 Russians would lose their jobs because of the cuts while 100 Americans would be forced to leave their posts. A senior administration official would only say that the U.S. had met the 455-employee cap the Russians imposed, affecting both American and Russian staffers -- although American staff would be reassigned.

Nauert warned that the U.S. could have gone further, in pursuit of "parity" in diplomatic staffing levels, but chose not to in order to avoid a "downward spiral" in the relationship.

"The United States hopes that, having moved toward the Russian Federation’s desire for parity, we can avoid further retaliatory actions by both sides and move forward to achieve the stated goal of both of our presidents: improved relations between our two countries and increased cooperation on areas of mutual concern," she said in a statement.

A senior administration official stressed that pursuit of better relations, saying today's actions was the U.S. "responding in this instance to the Russian desire for parity in the diplomatic relationship ... it is our hope that the Russians will recognize that since they were the ones who started the discussion on parity and we are responding and complying with what they required of us."

The closures will not affect Russian diplomats, according to the official. Staffers can be reassigned to other posts in the U.S. if Russia chooses. None will be expelled.

Acting Assistant Secretary for European and Eurasian Affairs John Heffern also conveyed the decision to Russian Deputy Chief of Mission Denis V. Gonchar at the Russian embassy in Washington. Russia's new Ambassador to the U.S. Anatoly Antonov begins his post Friday.

Ahead of the order, Russian officials had warned that further U.S. steps could be met with retaliation. Earlier on Thursday, Kremlin spokesperson Dmitry Peskov warned that "unfriendly" acts toward Russia cannot be left "without answer."

The U.S. ambassador to Moscow and Nauert have both said that was the result of the staff cuts and not meant as a retaliation, but Russian officials have accused the U.S. of trying to punish their citizens.

ABC News' Patrick Reevell contributed to this report.