Pope Francis appeared at Rome's Olympic Stadium on Saturday to provide a symbolic kick-off to a soccer match as part of celebrations for a Vatican-hosted "World Children's Day" festival.

Francis, 87, who has suffered from bouts of poor health, stood up from his chair by the side of the pitch as the ball was presented to him by a child accompanied by former Italian national team goalkeeper Gianluigi Buffon.

The pope, who is from Argentina and a keen soccer fan, gave the ball a gentle tap with his foot before watching the action unfold in a brief kickabout on the field at the stadium, home to the city's professional clubs AS Roma and Lazio.

The match ball was later handed back to the pope for him to  sign.

In response to a question from a child, the pope said he had been very happy when Argentina won the World Cup in 2022. 

But he said he had not enjoyed the notorious handball by Diego Maradona that helped them on their way to victory in the 1986 World Cup. Maradona famously remarked at the time that the quarter-final goal against England was scored "a little with the head of Maradona, a little with the hand of God".

Appearing in high spirits, Francis greeted children representing more than 100 countries, handing out sweets and encouraging those in the stadium to shake hands with each other in a gesture of peace.

Francis had earlier held an audience at the Vatican with children from war-hit regions, including Palestinians and Ukrainians.

The celebrations for the Vatican's inaugural "World Children's Day" continue on Sunday with a special mass at the Vatican followed by a reading by Italian actor Roberto Benigni.