Pope Francis has said it is a 'sin' to allow fear of immigrants to determine our actions, adding that while the fear itself is not a sin, 'the sin is to refuse to encounter the other, the different, the neighbour'.

Marking the World Day of Migrants and Refugees with a sermon during Mass at St Peter's Basilica yesterday, the Pope acknowledged that, 'It is not easy...to put oneself in the shoes of people so different from us' adding: 'Local communities are sometimes afraid that the newly arrived will disturb the established order, will "steal" something they have long laboured to build up.'

However, he went on to say: 'The sin is to allow these fears to determine our responses, to limit our choices, to compromise respect and generosity, to feed hostility and rejection...We often refuse to encounter the other and raise barriers to defend ourselves.'

The 81-year-old pontiff, who is himself the son of immigrants to Italy from Argentina, has consistently promoted the cause of migrants and asylum seekers since his election as pope in 2013.

On Sunday, at his invitation, several thousand migrants, refugees and immigrants from 49 countries joined Francis at the Mass.

The Pope said that local communities must 'open themselves without prejudices to their rich diversity, to understand the hopes and potential of the newly arrived as well as their fears and vulnerabilities'.

He added: 'Every stranger who knocks at our door is an opportunity for an encounter with Jesus Christ, who identifies with the welcomed and rejected strangers of every age.'

The Pope's comments came after Donald Trump made what were widely reported as vulgar remarks about immigrants last week.

Later, while greeting about 25,000 people in St Peter's Square, Francis reiterated a past theme of four ways of treating migrants: 'welcome, protect, promote and integrate'.