The US State Department confirmed to CNN that 60 US diplomats left Russia on Thursday, following the Russian government's expulsion of them in retaliation to similar moves by Washington.
A State Department spokesperson said that the diplomats left the country "in compliance with the Russian government's unwarranted decision to declare them persona non grata."
"We regret Russia's decision to expel our diplomats, dedicated professionals who have represented the United States with distinction in an effort to build bridges between our two countries, so that we might find a way to confront shared challenges together," the spokesperson said.
The White House announced last week it was expelling 60 Russian staffers and their families in response to the recent poisoning of a former double agent and his daughter in the United Kingdom, allegedly at the hands of the Kremlin. Russia was also ordered to close its consulate in Seattle.
The Trump administration claimed the expelled diplomats are Russian intelligence agents, and insisted their departure would make the US more secure.
More than 20 countries joined the US in expelling Russian diplomats last week out of solidarity with the UK. Russia denies it was behind the poisoning of Sergei and Yulia Skripal, calling the accusation "delirium and nonsense."
On Wednesday, the State Department confirmed the United States and Russia can replace diplomats in each other's countries who were expelled last week, describing the process as standard practice for cases in which targeted personnel are ejected as "persona non-grata," and cautioning that any new diplomats would be subject to approval on a "case-by-case basis."