CNN  — 

Russia has announced it is hitting several European Union representatives with tit-for-tat sanctions in response to those imposed by the bloc over the poisoning of Russian opposition leader Alexey Navalny.

The country’s foreign ministry said on Tuesday that the officials will be denied entry to Russia.

It did not name which representatives would be barred, but said it had relayed its decision to the ambassadors of Germany, France and Sweden after summoning them earlier on Tuesday.

A number of EU countries have planned measures against Russia since October, when an international chemical weapons watchdog confirmed that Navalny, who became gravely ill in August, was poisoned with a Novichok nerve agent.

France and Germany led a European push for sanctions following the verdict, and were supported by UK and EU leaders.

“We consider the adoption by the European Union at the behest of its leading Member States of illegitimate restrictive measures against some of our fellow citizens under the pretext of their alleged involvement in the incident with Russian citizen Alexey Navalny to be absolutely unacceptable,” the Russian Foreign Ministry said in a statement on Tuesday.

The officials will not be allowed to enter Russia, the ministry added. “We reaffirm that any unfriendly action by Western countries will inevitably be met with an adequate response.”

Laboratories in Germany, France and Sweden have previously said they were able to trace the presence of nerve agent Novichok in Navalny’s samples following his poisoning in Tomsk, Russia.

A CNN-Bellingcat investigation last week identified the Russian specialists who trailed Navalny for years before he was poisoned.

And in a further development uncovered on Monday, a Russian agent sent to tail the opposition leader revealed to Navalny himself how he was poisoned in August – with the lethal nerve agent Novichok planted in his underpants. The disclosure from an agent who belonged to an elite toxins team in Russia’s FSB security service came in a lengthy phone call.

Kremlin spokesperson Dmitry Peskov said on Tuesday that he hadn’t watched the video of the conversation, but slammed Navalny as a megalomaniac with a “Jesus” complex.