The Kremlin responded by saying it had no idea what the pope was talking about. And Ukraine’s ambassador to the Holy See, Andrii Yurash, said, “Ukraine doesn’t know about it.”

Mr. Zelensky did not leave Ukraine for the first 10 months of the war and his initial trips outside the country — including to Britain, France and the United States — were rare. In recent weeks, however, he has visited The Hague and Finland, and is expected to travel next to Germany.

The German government on Saturday announced its largest military aid package for Ukraine since the war began, saying it would provide 2.7 billion euros worth of weapons, including tanks, armored vehicles and substantial air defense systems.

Russia continued to strike Ukrainian cities and towns far from the front line overnight. Serhii Tiurin, a senior official in the Khmelnytskyi region of western Ukraine, said on Saturday that 21 people were injured in a Russian strike, which officials said hit a piece of critical infrastructure and caused a large fire.

Ukraine’s Air Force said in a statement that 21 Russian attack drones were launched at targets across the country overnight and that 17 were shot down.

Victoria Kim contributed reporting from Seoul, and Shashank Bengali from Istanbul.