What does it mean to consecrate a country to Mary?

And how can a country be consecrated if not everyone in it is even Christian?

The Holy Father will make a historic gesture on March 25, 2022, the feast of the Annunciation. While the Russian offensive on Ukrainian territory begins its 2nd month, the Pope will consecrate Russia and Ukraine to the Immaculate Heart of Mary. He has invited all bishops and priests around the world to join in the consecration.

To consecrate means “to dedicate to a sacred purpose.” The term is often used in the vocabulary of the Church for places (churches), persons (consecrated religious or lay persons) and liturgical objects, and, at the heart of the Christian faith, for the consecration of the Eucharist.