Imprisoned opposition leader Alexei Navalny was convicted of extremism charges and sentenced to 19 years in prison in a Russian court on Friday.

This is Navalny's fifth criminal conviction and his third and longest prison term, all of which his supporters believe are part of a deliberate Kremlin strategy to silence him. The new charges against Navalny are related to the activities of his anti-corruption foundation and statements made by his top associates.

Navalny is already serving a nine-year term on various charges that he claims were politically motivated. The extremism trial, which took place behind closed doors in the penal colony where he is imprisoned, ended with Navalny standing alongside his lawyers and co-defendant, wearing prison garb and appearing gaunt but defiant.

The judge announced the verdict and sentence in less than 10 minutes, a process that usually takes hours or even days in Russia. Navalny's new sentence is to be served concurrently with his current prison term for fraud and contempt of court. The prosecution had demanded a 20-year sentence, and Navalny himself expected to receive a lengthy term.

He has consistently rejected all the charges against him as politically motivated and accused the Kremlin of attempting to keep him behind bars for life. The authorities previously sentenced Navalny to two and a half years in prison for parole violations and another nine years on charges of fraud and contempt of court. It remains unclear whether he will serve the new sentence concurrently with these earlier convictions.

Navalny is currently serving his sentence in a maximum-security prison in Melekhovo, east of Moscow, where he has spent months in solitary confinement for disciplinary violations. Navalny's team and supporters have called for resistance and solidarity with the imprisoned politician.

On the eve of the verdict, Navalny released a statement on social media urging Russians to resist and support political prisoners. He emphasized the importance of not being intimidated and called on people to take action, whether it's distributing flyers, attending rallies, or finding safe ways to resist.

The United States State Department condemned Navalny's new sentence as an "unjust conclusion to an unjust trial" and called for his immediate release. The department criticized the lack of transparency and due process in the trial and accused the Russian authorities of trying to silence Navalny's calls for transparency and accountability.

Navalny's conviction and sentencing have raised concerns about the Russian judicial system and its use for political purposes. The UN human rights chief also expressed concern about judicial harassment and the instrumentalization of the court system in Russia.

Navalny's lawyers plan to appeal the verdict, which means it will not take effect until the appeal is ruled on. Although facing a harsh sentence, Navalny remains optimistic and believes in the importance of his work. He continues to be a vocal critic of the Kremlin and has exposed official corruption and organized major anti-Kremlin protests. Navalny's resilience and determination have garnered support both within Russia and internationally.