Ukrainian President met privately with the pope at the Vatican in May.
Ukrainian President Volodymyr Zelensky said he discussed Ukraine's peace formula in a call with Pope Francis on Thursday.
"We discussed our joint work to put Ukraine's Peace Formula into action," Zelensky said in a post on X, formerly Twitter.
"Over 80 countries are already involved in this process at the level of their representatives. And there will be more of them," he added.
Zelensky said he thanked Francis for his Christmas greetings "as well as his wishes for a just peace for all of us."
Zelensky has said that Ukraine's peace formula will next be discussed in Davos, Switzerland, but has not given a date.
As part of his peace efforts on Ukraine, the pope has sent a special envoy, Italian Cardinal Matteo Zuppi, to Kyiv, Moscow, Washington and Beijing.
In his Christmas Day message, the pope called for an end to multiple conflicts, including the one in Ukraine. In November, in a renewal of his persistent calls for an end to violence in Ukraine and the Middle East, he said "peace is possible" and that "we must not resign ourselves."
Zelensky said in October that he had invited Francis to Kyiv. The Ukrainian leader met privately with the pope at the Vatican in May.