Pope Francis ended the Roman Catholic Church's Holy Year of Mercy on Sunday by closing the Holy Door in the Vatican.

In a solemn ceremony the pontiff shut the Door of Mercy in St Peter's Basilica through which around 20 million pilgrims passed since it was opened on December 8, 2015. 

Holy Years normally take place every 25 years unless a Pope decrees an extraordinary one – such as the one that closed on Sunday – to bring attention to a particular need or topic.

The next one was to be held in 2025 but the 79-year-old Francis called a special year on the theme of mercy amid concerns about growing divisions and conflict in the world and polarisation among Catholics. It has been a major part of his push for a less judgmental and more inclusive Church.

Catholics around the world were asked to forgive each other and the Pope made numerous appeals to world leaders to make gestures of peace and reconciliation.

In his homily at a Mass before 70,000 people in St Peter's Square, celebrated together with 17 new cardinals installed on Saturday, he called for the spirit of hope and mercy to continue.

"Let us ask for the grace of never closing the doors of reconciliation and pardon, but rather of knowing how to go beyond evil and differences, opening every possible pathway of hope," he said.

During the year, both Cuba and Paraguay responded to papal appeals by granting amnesties to prisoners and the Pope held a historic meeting of reconciliation with the head of the Russian Orthodox Church after a rift of nearly 1,000 years.

But his many appeals for ceasefires in Syria and peace in places such as Ukraine achieved little result.

Division also reared its head within his 1.2 billion member Church. Last week, four conservative cardinals made a rare public challenge to Francis over some of his teachings in a major document on the family, accusing him of sowing confusion on important moral issues.