The White House condemned the poisoning of Vladimir Putin critic Alexei Navalny as “completely reprehensible,” hours after the German government confirmed the presence of nerve agent Novichok on the Russian opposition leader’s body.

“The United States is deeply troubled by the results released today. Alexei Navalny’s poisoning is completely reprehensible. Russia has used the chemical nerve agent Novichok in the past,” National Security Council spokesman John Ullyot said in a statement on Twitter. “We will work with allies and the international community to hold those in Russia accountable, wherever the evidence leads, and restrict funds for their malign activities.”

PUTIN CRITIC ALEXEI NAVALNY POISONED BY NOVICHOK, GERMANY SAYS 

Ullyot added that Russians have a right to “express their views peacefully without fear of retribution of any kind, and certainly not with chemical agents.”

Navalny is a famous critic of Putin and anti-corruption activist.

Navalny fell mysteriously ill on a flight back to Moscow from Siberia on Aug. 20 and was taken to a hospital in the Siberian city of Omsk after his plane was forced to make an emergency landing.

Two days later he was transferred to a German hospital, where doctors said last week there had been signs that the outspoken politician had been poisoned.

In a statement, the laboratory that carried out the toxicology tests said there was "unequivocal evidence of a chemical nerve agent" present.

Novichok, which means "newcomer" in Russian, applies to a group of advanced nerve agents developed by the Soviet Union in the 1970s and 1980s under the codename Foliant. Some variants of the agent are estimated to be five to eight times more toxic than VX nerve agents, the BBC reported.

Experts at a German hospital noticed similarities between the Navalny case and that of the 2018 Sergei Skripal attack. In that case, Skripal and his daughter Yulia were poisoned with military-grade Novichok.

The German government’s official statement described the attack on Navalny as an “astounding act” and asked the Russian government to offer an explanation.

“They wanted to silence him and I condemn this in the strongest possible terms, also on behalf of the entire federal government," German Chancellor Angela Merkel said.

RUSSIAN BLOGGER, ANTI-KREMLIN ACTIVIST ATTACKED OUTSIDE HIS APARTMENT

United Kingdom Prime Minister Boris Johnson also called on the Russian government to explain.

"It’s outrageous that a chemical weapon was used against Alexey Navalny," Johnson tweeted. "We have seen first-hand the deadly consequences of Novichok in the UK. The Russian government must now explain what happened to Mr Navalny – we will work with international partners to ensure justice is done."

The Kremlin said Wednesday it hadn’t been informed yet of Navalny being poisoned with a nerve agent.

“Such information hasn’t been relayed to us,” Kremlin spokesman Dmitry Peskov told the state news agency Tass.

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Navalny has been a thorn in Putin's side for the past decade. Following his collapse on the plane, Navalny's supporters immediately accused the Kremlin of poisoning his tea.

Fox News' Barnini Chakraborti contributed to this report.