'Serious questions' for Russia: World leaders react with horror to reports of Putin critic Navalny's death

World leaders on Friday reacted with dismay and suspicion to reports of the death of prominent Russian opposition leader Alexei Navalny in a Siberian penal colony.

Russian media reported, citing the prison service of the Yamalo-Nenets region where Navalny had been serving a lengthy sentence on what were widely considered to be politically motivated charges, that he had fallen ill and collapsed after a walk.

Navalny's team said they had yet to receive confirmation of the death and questioned the veracity of the announcement.

U.S. Vice President Kamala Harris told the Munich Security Conference on Friday that Washington was working to confirm the "terrible" news.

"Whatever story they tell, let us be clear, Russia is responsible, and we will have more to say on this later," she added.

Russia's Foreign Ministry said the response to Navalny's reported death from Western leaders is "self-exposing" at a time when no forensic medical examination is yet available.

NATO Secretary General Jens Stoltenberg said he was "deeply saddened and concerned" about the reports of Navalny's demise.

"All the facts have to be established and Russia has serious questions to answer," he told reporters.

"Alexei Navalny has been a strong voice for freedom, for democracy, for many years, and NATO and NATO allies have called for his immediate release for a long time."

The Kremin critic appeared in court via videolink earlier in the week, seemingly in good health and spirits despite the notoriously brutal conditions of the penal colony in which the 47-year-old was being held on a 19-year sentence.

Yet Russian news agency Interfax reported on Friday that he "felt unwell after a walk, almost immediately losing consciousness."

European Commission President Ursula von der Leyen said she was "deeply disturbed and saddened" by news of his death.

"Putin fears nothing more than dissent from his own people. A grim reminder of what Putin and his regime are all about. Let's unite in our fight to safeguard the freedom and safety of those who dare to stand up against autocracy," von der Leyen said.

U.S. Secretary of State Antony Blinken said if confirmed, Navalny's death underscores the "weakness and rot" of the Russian political system built by President Vladimir Putin, and laid the blame squarely at the door of the Kremlin.

"We'll be talking to the many other countries concerned about Alexei Navalny, especially if these reports bear out to be true."

British Prime Minister Rishi Sunak said in a post on social media platform X that "as the fiercest advocate for Russian democracy, Alexei Navalny demonstrated incredible courage throughout his life."

"My thoughts are with his wife and the people of Russia, for whom this is a huge tragedy," he added.

German Chancellor Olaf Scholz said he was "deeply saddened" by the news and that if confirmed, Navalny's death was a "terrible" sign of how Russia had changed as a country in recent years.

Navalny "stood up for democracy and freedom in Russia - and apparently paid for his courage with his life. This terrible news shows once again how Russia has changed and what kind of regime is in power in Moscow," he said in a post on X.

French Foreign Minister Stéphane Séjourné said on social media that Navalny had "paid with his life for his resistance to a system of oppression," according to a translation.

"His death in a penal colony reminds us of the reality of Vladimir Putin's regime," he added. "To his family, his loved ones and the Russian people, France offers its condolences."

Swedish Foreign Minister Tobias Billstrom said the announcement was "dreadful news," adding that "the ruthlessness against Navalny shows again why it is necessary to continue to fight against authoritarianism."

Russia: NATO accusations 'self-exposing'

Seven members of the Russian government were sanctioned by the U.S. in early 2021 for what has been independently confirmed as the poisoning of Navalny with a Novichok nerve agent in August 2020.

Navalny narrowly survived and was transported to Germany, but was arrested in January 2021 shortly after arriving back in Russia, sparking international outcry.

In response, Russian Foreign Ministry spokesperson Maria Zakharova said via X that "the instant reaction of NATO leaders to the news of Alexey Navalny's demise in the form of direct accusations vs Russia is self-exposing."

She added, "No forensic medical examination data IS available, yet the West has already voiced its 'conclusions'."