British flag flies in front of the British embassy building in Moscow, Russia, March 15, 2018. (REUTERS PHOTO)

MOSCOW, March 30 (Xinhua) -- Russian Foreign Ministry on Friday asked Britain to downsize its diplomats stationed in Russia to the same level as Russia has in Britain within a month in retaliation to measures imposed following the poison attack in Britain.

The ministry summoned British Ambassador to Russia Laurie Bristow to be presented with a strong protest over "provocative and unjustified actions of the British side," according to a statement published by the ministry.

"The ambassador was informed that, in response, the British side should, within a month, by appropriate reductions of its personnel, bring the total number of employees of the British Embassy in Moscow and the British Consulate General in Russia into line with the number of Russian diplomats and administrative and technical staff on long-term missions in the UK," the statement said.

The move was part of retaliatory measures against Britain after it expelled 23 Russian diplomats over the poisoning of a former Russian double agent in the British city of Salisbury earlier in March.

More than two dozens countries announced the expulsion of Russian diplomats in the wake of the UK's move, including the United States.

On Thursday, Russia announced its decision to expel 60 U.S. diplomats and shut the U.S. consulate general in St. Petersburg in retaliation for Washington's similar moves.