The Kremlin said on Wednesday Pope Francis's envoy would hold talks with President Vladimir Putin's advisor in Moscow as Russia "welcomed" the Vatican's peace efforts over Ukraine.
Cardinal Matteo Maria Zuppi began a Russia visit on Tuesday in a first such trip since Putin sent troops to Ukraine in February 2022.
High-ranking Catholic clerics are rarely seen in Moscow, which no Pope has ever visited.
Zuppi's trip comes several weeks after he met Ukrainian President Volodymyr Zelensky in Kyiv.
"We highly value the efforts and initiatives of the Vatican in looking for a peaceful solution to the Ukrainian crisis," Kremlin spokesman Dmitry Peskov said. "We welcome them."
He said Zuppi was due to hold talks with Putin's foreign policy advisor Yuri Ushakov.
The Vatican said the purpose of Zuppi's visit was to "encourage gestures of humanity, which can help promote a solution to the current tragic situation and find ways to achieve a just peace."
Zuppi's meeting with Zelensky in early June ended without much progress, but Kyiv said the cleric could help in bringing home Ukrainian prisoners of war and children taken to Russia during the offensive.
The 67-year-old Italian cardinal hails from the Sant'Egidio Catholic Community, which specialises in diplomacy and peace efforts.
Pope Francis has been criticised by both Kyiv and Moscow during the conflict.
A Russian Roman Catholic prelate, Nikolay Dubinin, told state media this week that Zuppi "hoped" to meet Patriarch Kirill, but the Russian Orthodox Church did not confirm this.
Kirill is a vehement supporter of Putin's Ukrainian offensive, which he has described in holy terms.
Zuppi was due at a mass in Moscow's main Catholic cathedral on Thursday evening.
Almost a thousand years after a schism broke apart the churches, spiritual relations between the Vatican and Moscow remain icy.