WASHINGTON (NewsNation Now) — The U.S. Treasury Department on Tuesday imposed sanctions on seven Russian officials over the poisoning and jailing of opposition leader Alexei Navalny, whose detention drew tens of thousands of protesters out into the streets of Russian cities this winter.

Among those blacklisted by the Treasury were Andrei Yarin, the chief of the Kremlin’s domestic policy directorate; Alexander Bortnikov, the Director of the Federal Security Service (FSB); and deputy ministers of defense Alexei Krivoruchko and Pavel Popov, among others, according to a statement.

The Biden administration also announced sanctions under the U.S. Chemical and Biological Weapons Control and Warfare Elimination Act for 14 businesses and another enterprise, most of which it said were involved in the production of biological and chemical agents.

The U.S. intelligence community concluded with high confidence that Russia’s Federal Security Service used the Russian nerve agent Novichok on Navalny last August, a senior administration official said.

“The Kremlin’s use of chemical weapons to silence a political opponent and intimidate others demonstrates its flagrant disregard for international norms,” Treasury Secretary Janet Yellen said in a statement. “We join the EU in condemning Alexei Navalny’s poisoning as well as his arrest and imprisonment by the Russian government.”

Tuesday’s sanctions would be the first of several steps by the Biden administration to “respond to a number of destabilizing actions,” said one of the administration officials, who briefed reporters on condition they not be identified further.

The sanctions are the first against Russia by the Biden administration, which has pledged to confront President Vladimir Putin for alleged attacks on Russian opposition figures and hacking abroad, including of U.S. government agencies and U.S. businesses.

The Biden administration had forecast for weeks actions against Russia. Besides the Navalny sanctions, officials have said the administration plans to respond soon to the massive Russian hack of federal government agencies and private corporations that laid bare vulnerabilities in the cyber supply chain and exposed potentially sensitive secrets to elite Kremlin spies.

The European Union also imposed sanctions Tuesday on four senior Russian officials over Navalny’s jailing.

The 27-nation bloc imposed bans on travel and froze the assets in Europe of Alexander Bastrykin, head of the Investigative Committee of the Russian Federation, Igor Krasnov, the prosecutor general, Viktor Zolotov, head of the National Guard, and Alexander Kalashnikov, head of the Federal Prison Service.

EU headquarters said the four were listed “over their roles in the arbitrary arrest, prosecution and sentencing of Alexei Navalny, as well as the repression of peaceful protests in connection with his unlawful treatment.”

Navalny, 44, an anti-corruption investigator, was arrested in Moscow in January upon returning from Germany, where he spent five months recovering from a nerve-agent poisoning that he blames on the Kremlin. Russian authorities have rejected the accusation.

In February, a court sentenced Navalny to two years and eight months in prison for violating the terms of his probation while recuperating in Germany. The sentence stems from a 2014 embezzlement conviction that Navalny has rejected as fabricated.

The European Court of Human Rights has also ruled that it’s unlawful.

Navalny’s arrest and imprisonment have fueled a huge wave of protests across Russia. Authorities responded with a sweeping crackdown, detaining about 11,000 people, many of whom were fined or given jail terms ranging from seven to 15 days.

Navalny was transferred to a penal colony outside Moscow to serve his prison sentence, a public commission said on Sunday, weeks after he returned to Russia after being poisoned.

Ruslan Vakhapov, a local activist of the prisoners’ rights group Jailed Russia, described conditions as particularly severe.

“In short, it’s a bad colony,” Ruslan Vakhapov told Reuters by phone.