Russia's Foreign Ministry does not rule out ordering the United States to cut its diplomatic staff in Russia to 300 people or below, the RIA news agency cited Georgy Borisenko, the head of the ministry's North America Department, as saying on Wednesday.
In July, Moscow ordered the United States to cut the number of its diplomatic and technical staff working in Russia by around 60 percent, to 455, part of a diplomatic row.
The figure of 455 was meant to mirror the total number of Russian diplomats working in the United States, but also included Russian nationals working at the United Nations in New York, Borisenko told the agency.
"The fact that in the summer we took into account the people working for Russia's mission at the UN, this was good will," Borisenko told RIA.
"If they haven't appreciated this, we have the full right to reduce ... the number of US diplomats," he said, saying Moscow could stop taking Russian UN staff into account when calculating what parity between the two countries meant.
"In this case, the number of American personnel in Russia should decline to a level of 300 or below."