Ukraine's President Volodymyr Zelensky is visiting Rome, where he will meet political leaders and have an audience with Pope Francis,
BBC reports.
"An important visit for approaching victory of Ukraine!" he tweeted as he landed in the Italian capital.
He will meet Italian PM Giorgia Meloni and President Sergio Mattarella and head for the Vatican later on Saturday.
A huge security operation has been launched, with more than 1,000 police deployed and a no-fly zone over Rome.
Pope Francis has often said that the Vatican stands ready to act as a mediator in the conflict between Russia and Ukraine.
Earlier this month, he stated that the Vatican was working on a peace plan to end the war, saying that the mission was "not yet public. When it is public, I will talk about it."
But the relationship between Ukraine and the Vatican has sometimes been uneasy.
Last August, Ukraine's ambassador to the Vatican took the unusual step of criticising the Pope after the pontiff referred to Darya Dugina, the daughter of a Russian ultra-nationalist figure, who was killed by a car bomb, as an "innocent" victim of war.
Saturday will be the first time President Zelensky and Pope Francis have met since Russia invaded Ukraine. The pair did meet in 2020.
The visit comes after Russia carried out a new wave of air strikes on Kyiv and other Ukrainian cities overnight.
Three people were injured in the southern city of Mykolaiv and in the western city of Khmelnytsky. Critical infrastructure, as well as homes and government buildings, was also hit.
Explosions were reported on Friday in the Russian-occupied city of Luhansk, about 90km (56 miles) behind the front line in eastern Ukraine. Russian-backed separatist forces in the region accused Kyiv of using Storm Shadow missiles, which the UK said it had supplied Ukraine with earlier this week.
There were also more reports of blasts in Luhansk on Saturday.
Meanwhile, the German government unveiled its biggest military aid package for Ukraine yet, worth €2.7bn (£2.4bn). Mykhailo Podolyak, an adviser to President Zelensky, said the aid indicated that Russia was "bound to lose and sit on the bench of historical shame".
Earlier this week, German media reported that President Zelensky was planning to visit Germany following his trip to Italy, although this has not yet been confirmed.