Russia has expelled US deputy chief of diplomatic mission in Moscow, the embassy's spokesman Jason Rebholz said on Thursday amid heightened tensions over Ukraine.

Bart Gorman, the second-highest official of the US embassy in Moscow, left Russia late January, Rebholz said in an interview with the state-run RIA news agency.

The move came a month after 50 Russian diplomats and their families had to leave the US since their visas were not extended, a development Moscow termed as "an expulsion."

Commenting on Gorman's departure, the US State Department called on Russia "to end its baseless expulsions of US diplomats and staff and to work productively to rebuild our missions."

"Now more than ever, it is critical that our countries have the necessary diplomatic personnel in place to facilitate communication between our governments," a spokesperson said.

US and NATO officials argue that the risk of a Russian invasion of Ukraine remains high, despite Moscow saying it has withdrawn some of its troops away from the border.

Source: Anadolu Agency