The United States on Tuesday imposed sanctions on seven senior Russians over the poisoning of Kremlin critic Alexei Navalny in August, last year, AFP reported. The country said its intelligence concluded that Moscow was behind the Opposition leader’s poisoning. “The intelligence community assesses with high confidence that officers of Russia’s Federal Security Service FSB used a nerve agent known as Novichok to poison Russian opposition leader Alexei Navalny on August 20, 2020,” a senior US official said.

Also read: President Vladimir Putin slams West for using critic Alexei Navalny to ‘contain’ Russia

Among those who were slapped with sanctions was the director of Russia’s FSB security agency. The US  Treasury Department said that Alexander Bortnikov, who since 2008 has led the KGB’s successor, was one of seven senior Russian officials whose US assets will be frozen, with any US transactions with them subject to prosecution.

The officials said that the United States would restrict exports to Russia as it vowed that President Joe Biden would take a harder line than his predecessor Donald Trump, who voiced admiration for Putin.

“We’re sending a clear signal to Russia that there are clear consequences to the use of chemical weapons,” another official said.

Also read: Moscow court upholds Putin critic Alexei Navalny’s jail term

In action coordinated with the EU, the United States renewed demands that Russia free Navalny, who was arrested in January upon his return to Moscow as he spurred massive rallies through his allegations of corruption by President Vladimir Putin.

Navalny, 44, fell violently ill when he was on a domestic flight.

Also read: Alexei Navalny begins prison sentence for parole violation

He was rushed to treatment in Germany where doctors said he had been poisoned with Novichok, a nerve agent developed by Soviet researchers and which was also blamed in a 2018 attack in England against Russian double-agent Sergei Skripal and his daughter and Yulia.