After his Angelus address on Sunday 20 March, Pope Francis said:

I invite every community and all the faithful to unite with me on Friday 25 March, the Solemnity of the Annunciation, for the Solemn Act of Consecration of humanity, especially Russia and Ukraine, to the Immaculate Heart of Mary, so that she, the Queen of Peace, may help us obtain peace.

The Act of Consecration will be prayed during the 24 Hours for the Lord Lenten penitential service in St. Peter’s Basilica, which begins at 5pm Rome time (4pm Irish time).
It will be will be broadcast across Vatican News channels – radio, website, YouTube, and Facebook – with English-language commentary.

Text of Act of Consecration available here.

Archbishop Dermot Farrell  will join Pope Francis in the consecration of Russia and Ukraine to the Immaculate Heart of Mary.
The ceremony will be held at 4pm in the Church of the Sacred Heart, Donnybrook.
Archbishop Farrell invites the priests, deacons and faithful of the Archdiocese to join him on Friday in prayer for peace in the world, especially between Russia and Ukraine.

See report on Vatican News website here.