Pope Francis has made an impassioned appeal to Russian President Vladimir Putin to stop “this spiral of violence and death” in Ukraine, saying the crisis risks a nuclear escalation with uncontrollable global consequences.

In an address dedicated to Ukraine to thousands of people in St Peter’s Square, Francis appealed to Ukrainian President Volodymyr Zelensky to remain open to any “serious peace proposal”.

Pope Francis said he was making an urgent appeal “in the name of God” for an end to the conflict and said it was “absurd” the world was risking a nuclear conflict.

Speaking two days after Mr Putin proclaimed the annexation of nearly a fifth of Ukraine and placed the regions under Russia’s nuclear umbrella, the Pope defended all countries’ right to “sovereign and territorial integrity”.

“My appeal goes above all to the president of the Russian Federation, begging him to stop this spiral of violence and death, even out of love for his own people,” Pope Francis said.

“On the other side, pained by the enormous suffering of the Ukrainian population following the aggression it suffered, I address an equally hopeful appeal to the president of Ukraine to be open to a serious peace proposal.”

Kyiv and its Western allies have condemned Mr Putin’s annexations as illegal and Mr Zelensky has said his forces will continue their fight to recapture all Ukrainian territory occupied by Russian forces.