The Vatican has revealed, the mayor of Kiev had issued a formal invitation for Pope Francis to visit Ukraine's capital earlier this month. 

On Tuesday, a Vatican official said Vitaly Klitshko had written a letter to the Pontiff urging him to visit the city, as he believed his presence in Kiev would be "key for saving lives and paving the path to peace."

The Vatican confirmed the Pope had received the letter but made no mention of a future trip. 

But in his letter, Klitshko said that if a trip was not possible, a live or recorded video conference would also be helpful. 

"We kindly ask for a joint video conference, to be recorded or broadcast live. Efforts will be made to include President Zelenskyy in this call."

It continued: "We appeal to you, as a spiritual leader, to show your compassion, to stand with the Ukrainian people by jointly spreading the call for peace."

This is not the first time Kiev's mayor calls on religious leaders to take stance against Russia's actions. On March 5th, Klitshko published a video on Twitter urging religious leaders from around the world to come to Kiev.

"What is happening in the heart of Europe touches the hearts of all the inhabitants of our planet, who love justice and values of goodness, regardless of their region or religion. I expressly appeal to religious leaders to take a stand and assume the moral function that is incumbent upon them and to proudly assume the responsibility of their religions for peace," Klitshko said. 

Pope Francis has so far avoided to publicly condemn Russia by name for its invasion. However, it has rejected Russia's statement that it is carrying out 'a special military operation' but called it a war that is causing 'rivers of blood and tears.'

The Pontiff has also said "the Holy sea is willing to do everything to put itself at the service of peace" and has sent two cardinals as papal envoys to Ukraine.