The Kremlin has shrugged off new Western sanctions over the poisoning and arrest of Russian opposition leader Alexei Navalny as unfounded and pointless, but warned that Moscow will retaliate.

US president Joe Biden’s administration sanctioned seven Russian officials on Tuesday, along with more than a dozen government entities, over the nerve-agent attack on Mr Navalny and his subsequent jailing.

It co-ordinated the move with the European Union, which expanded its own sanctions on Tuesday.

Commenting on the US and the EU decisions, Kremlin spokesman Dmitry Peskov said the sanctions against top officials that included a freeze on their bank accounts duplicated Russia’s own law that bans them from having financial and other assets abroad.

Speaking with reporters, he said: “These people don’t make foreign trips anyway and they don’t have the right to open accounts in foreign banks or have any other foreign assets.”

At the same time, he added that the US and EU restrictions “represent meddling in Russia’s internal affairs” and are “absolutely unacceptable, inflicting significant damage to the already poor ties”.

Mr Peskov warned that Russia would now choose a “response that would best serve our own interests”, adding that the relevant state agencies would draft their proposals and submit them to the Kremlin.

“The principle of reciprocity in relations between states can’t be abandoned,” he said.

Mr Navalny, the most prominent critic of Russian president Vladimir Putin, fell sick on August 20 during a domestic flight in Russia and was flown, while still in a coma, to Berlin for treatment two days later.

Labs in Germany, France and Sweden, and tests by the Organisation for the Prohibition of Chemical Weapons, established that he was exposed to a Soviet-era Novichok nerve agent.

Russian authorities have denied any involvement in the poisoning.

Mr Navalny was arrested on January 17 upon returning from Germany, where he spent five months recovering from the poisoning.

His arrest triggered massive protests, to which the Russian authorities responded with a sweeping crackdown.

Last month, Mr Navalny was sentenced to two-and-a-half years in prison for violating the terms of his probation while convalescing in Germany.

The sentence stems from a 2014 embezzlement conviction that Mr Navalny has rejected as fabricated, and which the European Court of Human Rights has ruled to be unlawful.

Mr Navalny was last week sent to serve his sentence in a prison outside Moscow, despite the European Court of Human Rights’ demand for his release which cited concerns for his safety.