Russia has declared 40 German diplomats "personae non gratae" in a tit-for-tat move, the Russian Foreign Ministry said on Monday.

The ministry summoned German Ambassador to Russia Geza Andreas von Geyr on Monday in protest over Germany's decision to declare 40 Russian diplomats working in Germany "personae non gratae" earlier in April, the ministry said.

The ministry called Germany's motives behind the expulsion of the Russian diplomats "unacceptable," and informed the ambassador that 40 German diplomats would be declared "personae non grata" in a symmetrical response.