Pope Francis left Rome on Friday (April 28) on a three-day trip to Hungary, where the war in Ukraine, migration and Europe's Christian roots are expected to top the agenda in his public addresses and private talks with nationalist Prime Minister Viktor Orban.

It will be his first trip since he was hospitalised for bronchitis in March.

While main purpose of the trip is meeting with Hungarian Catholics, Francis acknowledged on Sunday (April 23) that its content is affected by current events, specifically Russia's invasion of Ukraine.

In March, Orban said Hungary and the Vatican are the only two European states that can be described as "pro-peace" regarding Ukraine.

Both Orban 59, and the pope, 86, have called for a ceasefire and negotiations to end the war and Francis has urged Ukraine to be open to dialogue with "aggressor" Russia, something Ukraine so far has ruled out.

Hungary, which supports a sovereign Ukraine but still has strong economic ties to Russia, has refused to send weapons to Ukraine.

But while the pope has often called for a general ban on arms trafficking and reduction in weapons manufacturing, he has also said sending arms to Ukraine is morally acceptable if they are used only for self-defence.

Orban and the pope also differ widely on how to handle migration from the Middle East and Africa as well as on the importance of the European Union, with which Hungary has had many disagreements.