Image source, Reuters

Former US secretary of state Hillary Clinton has posted a tribute to Alexei Navalny on X, external (formerly Twitter).

“Listen, I've got something very obvious to tell you. You’re not allowed to give up. If they decide to kill me, it means that we are incredibly strong,” she writes, quoting Navalny from a BBC documentary from 2022.

She also sends her "deepest condolences" to Navalny's family and to the Russian people for his death.

Biden adds that this is the time for "greater unity" among Nato allies to stand against Vladimir Putin, in spite of the Russian president's "desperate attempts to stamp out any opposition".

The US president sends his condolences to Navalny's staff and his family.

"God bless Alexei Navalny, his courage will not be forgotten," he adds.

Image source, Reuters

US President Joe Biden is speaking from the White House after Navalny's death.

"I'm both not surprised and outraged at the news," he says.

Biden says he bravely stood up to violence by the Putin regime, for which he was incarcerated, poisoned - and none of that stopped him.

Biden lauds Navalny's bravery, saying he could have lived abroad in exile after he was poisoned in 2020 - but he didn't.

He was so many things Putin was not - he was brave, dedicated, and believed that a Russia for everybody was a Russia "worth fighting for".

"Make no mistake," Biden adds: "Putin is responsible for Navalny's death."

Moscow city authorities have warned people against public demonstrations in the Russian capital following the news of the death of opposition figure Alexei Navalny.

In a statement reported by Russian news agencies, the city's prosecutor's office notes a number of online calls for a "mass rally", and says it “considers it necessary to warn against violating the law".

Russian law requires organisers to seek permission from the authorities for any mass assembly.

Image source, Navalny Team

Allies of Alexei Navalny have released a statement saying that they believe that it is "highly likely" that the Russian opposition politician has been killed in a prison, but they can't independently confirm it yet.

Ivan Zhdanov, the director of Navalny's Anti-Corruption Foundation, made these statements during a broadcast on the opposition leader's YouTube channel alongside his spokesperson, Kira Yarmysh.

She adds that Navalny’s lawyer will fly to the penal colony late at night and will arrive tomorrow morning alongside relatives of the Kremlin critic.

If you'd like to read more about this story, our colleagues in the BBC Russian service are also running a live page on Navalny's death.

Click here to read their Russian language coverage.

James Waterhouse
Ukraine correspondent in Kyiv

“Obviously, he was killed by Putin,” was President Volodymyr Zelensky’s blunt assessment of what happened to Alexei Navalny.

What his comments weren’t accompanied by was a tribute to the jailed Kremlin critic.

Is that surprising? Navalny did, after all, condemn Russia’s full-scale invasion of Ukraine.

A year ago, he called it “unjust” and accused Putin of trying to hide political and economic problems in Russia.

He even called for Moscow to be charged with war crimes and made to pay Kyiv for the damage this war has caused.

Perhaps Ukraine’s president remembers Navalny saying Crimea "will remain part of Russia and will never again become part of Ukraine in the foreseeable future" after its annexation in 2014, even though he didn’t support it.

Many Ukrainians you speak to certainly haven’t forgotten.

Maybe Zelensky also recalls Navalny’s vocal support for Russia when its troops invaded South Ossetia in Georgia in 2008.

Regardless, one Ukrainian hope of winning this war relies on a regime collapse in Russia. Alexei Navalny was a prominent opposition figure that perhaps gave hope that could happen.

An outside bet, but that’s gone now.

Image source, Reuters

Any suggestion that the Kremlin is responsible for Alexei Navalny's death is "completely unacceptable", Putin spokesman Dmitry Peskov says, as reported by Russia's Tass news agency.

Peskov says the reaction from Western leaders to Navalny's death was "hysterical".

Earlier, the Russian parliament's speaker Vyacheslav Volodin had blamed the West for the Kremlin critic's death.

Image source, Get

US Republican presidential hopeful and former UN ambassador Nikki Haley has laid the blame for Alexei Navalny's reported death squarely at the feet of Vladimir Putin - and used the incident as a way to attack her main rival, Donald Trump.

In a post on X, the platform formerly known as Twitter, Haley said that "Putin did this".

"The same Putin who Donald Trump praises and defends. The same Trump who said: 'in all fairness, you're saying he killed people. I haven't seen that'."

Trump has yet to comment on Navalny's death.

Haley has repeatedly criticised Trump for his relationship to foreign leaders, particularly Putin.

Earlier this week, for example, a satirical statement from her campaign suggested that Trump would send a love letter to Putin to mark Valentine's Day.

Imogen Foulkes
BBC Geneva Correspondent

The UN Human Rights Office says it is "appalled" by the reported death of Alexei Navalny, adding that it should be investigated by an independent body.

In a statement issued in Geneva the UN office said it had repeatedly raised concerns about the imprisonment of Navalny, which "appeared to be arbitrary".

UN human rights chief Volker Türk publicly called for his release last summer, saying his lengthy sentence suggested Russia was using the court system for political purposes.

"If someone dies in the custody of the State," the UN statement adds, "the presumption is that the State is responsible."

It adds that this "responsibility can only be rebutted through an impartial, thorough and transparent investigation carried out by an independent body".

Image source, EPA

State Duma speaker Vyacheslav Volodin is the latest Russian official to weigh in on Navalny's death, blaming Western leaders.

"All of them, their names are well-known, from the Nato secretary-general and the US leadership to Scholz, Sunak and Zelensky, are guilty of Navalny's death," the politician said on his Telegram channel.

"It is they who have made a huge number of failed decisions and cling to their positions who benefit from his death."

We've also had these comments from European Commission President Ursula von der Leyen.

Speaking in Munich, she says the news of Navalny's death is "horrible", and the world has "lost a freedom fighter".

Politicians from across the continent of Europe continue to react to Navalny's death.

French President Emmanuel Macron said that in Russia "free spirits are sent to the Gulag and condemned to death" as he shared his "anger and indignation" in a post on X.

"I pay tribute to the memory of Alexei Navalny, his dedication, his courage. My thoughts go out to his family, loved ones and to the Russian people," Macron added.

Poland's Foreign Minister, Radoslaw Sikorski, told the BBC's Chief International Correspondent Lyse Doucet that Navalny would be remembered as "the best Russian president that Russia never had".

He said Navalny was a "victim of Russian fascism" and that he was "beyond brave" in facing Putin. He added that even if no-one "pulled the trigger", it was the conditions that were created for him that killed him as he was imprisoned on fake charges.

Meanwhile Italian Foreign Minister Antonio Tajani said on X that Navalny died "after years of persecution in prison" adding that the Italian government "will always be at the side of those who fight for democracy, for freedom of thought and for the inalienable rights of every human being".

Estonian Prime Minister Kaja Kallas, who has just been added to Russia's wanted list, said on X that Navalny's death was "yet another dark reminder of the rogue regime we’re dealing with – and why Russia and all those responsible must be held accountable for each of their crimes".

Image source, Getty Images

We've been hearing more personal reaction to the death of Alexei Nalvany, this time from best-selling Russian crime writer Boris Akunin.

Speaking to the BBC World Service's Newshour programme, Akunin - a vocal critic of Putin who is wanted in Russia for speaking out against the war in Ukraine and now lives in exile in the UK - says he is "totally devastated" by the news.

Bernd Debusmann Jr
US Reporter

Image source, Gett

So far, we've not directly heard from US President Joe Biden about Alexei Navalny's death - but we surely will a little later today.

Later on Friday, Biden is heading to East Palestine, Ohio, where last year a toxin-laden train derailed and devastated the town.

He's scheduled to give remarks there at 1645 EST (2145GMT).

Additionally, White House Press Secretary Karine Jean-Pierre will speak to reporters aboard Air Force One at about 1400 EST (1900 GMT) and is sure to be asked about Navalny.

We've already briefly heard from Vice President Kamala Harris, who is attending the Munich Security Conference.

“If confirmed, this would be a further sign of Putin’s brutality," she said. “Whatever story they tell, let us be clear, Russia is responsible."

Harris also vowed that the US would have more to say about Navalny's death "later".

Image source, Getty Images

Celebrated former world chess champion and strident Kremlin critic Garry Kasparov has posted a strongly worded series of posts on X, external about Alexei Navalny's death.

"Putin is Navalny's killer," he says, but also criticises Western governments for not taking a stronger stance against his treatment by the Kremlin.

"My rage and eternal scorn toward the Western politicians who treated Navalny's poisoning and jailing as just another negotiating point with Putin," he says, referencing his repeated imprisonment and his poisoning with Novichok in 2020.

"Big talk, no action, more blood on their hands."

Kasparov calls Navalny a fighter, and adds that Western politicians "should keep his name out of their mouths" unless they are willing to fight too.

Vitaly Shevchenko
Russia editor, BBC Monitoring

Alexei Navalny’s death is a tragic illustration of the downward slide Russia has been on since President Putin came to power.

More than 20 years ago, various political parties and leaders were still able to mount a credible challenge to Vladimir Putin, and he himself said that Russia joining Nato was a possibility.

Then, the media were silenced and critics were jailed, forced into exile or killed.

When Russia invaded Ukraine in 2014, Moscow pretended it was not its troops wearing uniforms without insignia in Crimea and Donbass.

Now, the masks are off, and the gloves are off.

By the time Navalny died, the Kremlin had all but quashed domestic opposition.

If it is true that - as his associates allege - Navalny was killed by the authorities, it was less to achieve a political advantage, but rather simply because they can.

We reported earlier that the wife of Alexei Navalny has been speaking at the Munich Security Conference after news broke of her husband's death.

In the video above we hear Yulia Navalnaya receive a huge round of applause after talking about Alexei and the reports of his death.

Frank Gardner
BBC News, at the Munich Security Conference

Reactions to Navalny's reported death amongst delegates at this high-profile security gathering range from outrage to quiet resignation.

Vitali Klitschko, the Mayor of Kyiv, told the BBC it was a message to anyone "who had a different opinion to Putin or the Russian government that they will be killed or put into prison".

Lt.Gen Ben Hodges, a former Commander of US Land Forces in Europe, said he was not surprised, given the previous attempt on Navalny’s life, but it was still appalling news.

Ursula Von Der Leyen said the EU Commission was waiting for confirmation from the family before commenting.

Germany was where Navalny was treated in hospital for his Novichok nerve agent poisoning, allegedly by Russian GRU agents, and it was from here that he returned to Moscow to face arrest and imprisonment.

Image source, Getty Images

Vladimir Putin "should be accountable" for Alexei Navalny's death, says UK Foreign Secretary David Cameron on X, external (formerly Twitter), without specifying what kind of repercussions the Kremlin should face.

And speaking on the sidelines of the Munich Security Conference, Cameron calls Navalny "an incredibly brave fighter against corruption" who "gave up everything" for what he believed in.

Cameron adds that there should be no doubt about the "dreadful nature of Putin's regime in Russia after what has just happened".