Pope Francis spoke of his “great desire to go to Kiev” in an exchange with reporters who accompanied him on his flight to Canada on July 25.

The Pope has repeatedly said that he would like to visit Ukraine, to do whatever he can to end the fighting there. He has also spoken of an ambition to travel to Moscow—a trip that no Roman Pontiff has ever made.

Ukrainian Catholic leaders have expressed misgivings about a papal trip to Moscow, suggesting that—particularly if he travels to Russia before Ukraine—he could be showing sympathy for the aggressor in the current conflict.