At the second Vatican Council, in its decree on ecumenism the Catholic Church officially embraced the ecumenical movement in its goal of restoring the full visible unity of the one body of Jesus Christ:
"Today, in many parts of the world, under the influence of the grace of the Holy Spirit, many efforts are being made in prayer, word, and action to attain the fullness of unity which Jesus Christ desires. This sacred council, therefore, exhorts all the Catholic faithful to recognize the signs of the times and to take an active and intelligent part in the work of ecumenism."
Source: Fr. Peter Hocken - Pentecost and Parousia, Peter Hocken - p. 19 [Unitatis Redintegratio 4 Decree on ecumenism of the second Vatican Council]