Alexei Navalny’s wife of 24 years vowed Friday that President Vladimir Putin “will be brought to justice” over the “horrific news” of her husband’s death in custody.

Looking distraught but stoic at the Munich Security Conference in Germany, Yulia Navalnaya, 47, said she could not be certain her husband was dead because “Putin and his government… lie constantly.”

But if Navalny were indeed dead, she said, Putin and his cohorts “will be punished for what they have done to our country, for what they have done to my family, for what they have done to my husband.”

“They will be brought to justice. And this day will come soon,” she said.

The new widow told the conference — whose attendees include Vice President Kamala Harris — that world leaders need to unite to “defeat this evil, to defeat this horrifying regime in Russia.”

“This regime and Vladimir Putin should be personally held accountable for all the atrocities they have committed in our country over the past years,” she added.

The mother of Navalny’s two children — daughter Daria and son Zakhar — spoke just hours after Russia’s prison service announced the death of her husband, claiming he collapsed while on a walk at the remote prison where he had been transferred in December.

Yulia Navalnaya said that after hearing the “horrific news” she debated whether to remain at the conference or immediately jet off to see their children.

“And then I thought, ‘What would Alexei have done in my place?’ And I’m sure that he would have been standing here on this stage,” she said.

Navalnaya’s brief but powerful speech was met with a standing ovation from the audience.

Her husband, Putin’s fiercest critic, was last seen in public Thursday when he attended a court hearing via video link that showed him looking healthy and cracking jokes.

His mother, Lyudmila Navalnaya, was quoted by the Russian newspaper Novaya Gazeta as saying that when she last saw him Monday, her son had been “alive, healthy and happy.”

Secretary of State Antony Blinken met with Navalnaya at the summit in Germany and expressed his condolences, the State Department said.

Blinken “reiterated that Russia is responsible for his death.”