Moscow, with the Kremlin in the background.

Russia will definitely retaliate for the expulsions of Russian diplomats by multiple Western and east European governments, Kremlin Spokesman Dmitry Peskov said Wednesday.

Peskov said Moscow would hit back against the mass expulsions of diplomats by the U.K., the U.S. and other allies "but will do so at the appropriate time," Reuters reported.

Peskov, speaking at a press conference, gave no details on what Russia's response would be but said it would correspond to Russian national interests.

He said he hoped that countries carrying out expulsions will "properly examine British information" on the poisoning of former Russian spy Sergei Skripal and his daughter Yulia on British soil in early March.

The U.K. said it was almost certain that Russia carried out the attack using a military-grade, Russian-made nerve agent, but Russia denies any involvement.