Mr Higgins also took in a visit to Venice on Sunday
President Michael D Higgins is in Rome for a meeting with Pope Francis.
On Sunday, the president and Mrs Higgins visited Venice - taking in the Irish Pavilion at La Biennale, the world's largest and oldest international art exhibition.
This included an installation by Irish artist Jesse Jones.
The president met Mr Jones, as well as representatives from organisations involved in the exhibition - including Culture Ireland and the Arts Council.
In Rome, the president held a private meeting with Pope Francis.
During their meeting, the two men discussed a wide range of issues - including migration, climate change, sustainable development and global poverty.
The president and pope also agreed that there can be no resolution to issues faced without an alternative to what the pope referred to as 'the globalisation of indifference'.
In a statement, Áras an Uachtaráin says President Higgins and Pope Francis "agreed on the need for the sense of urgency that attaches to present challenges to be recognised in the agendas of meetings such as the upcoming G7 meeting in Taormina, and acceptance of the need to craft new and effective responses to global challenges.
"In particular, they agreed on the need to turn commitments on which the public had placed their trust into outcomes and action."
The president was also informed of, and welcomed, the appointment of Archbishop Okolo as Papal Nuncio to Ireland.
Following the meeting with the pope, President Higgins is meeting the Secretary of State of the Vatican Cardinal Parolin.
In the afternoon, the president will meet with Irish clergy and lay staff working at the Vatican.
This will take place at a reception at the Irish College in Rome.