VATICAN CITY (CNA/EWTN News) - Even though World Youth Day doesn't start until next week, thousands of pilgrims from throughout the world are already descending on Krakow ahead of the official event.

In a July 19 video message Pope Francis sent his greetings to the youth of Poland and the world who will attend the largest recurring gathering of youth in the Catholic Church.

"I look forward to meeting the young people from throughout the world gathered in Kraków and having the opportunity to meet the beloved Polish nation," he said.

"My entire visit will be inspired by Mercy during this Jubilee Year, and by the grateful and blessed memory of Saint John Paul II, who instituted the World Youth Days and was the guide of the Polish people in its recent historic journey towards freedom."

St. John Paul II, who was from Poland, established World Youth Day in 1985; the first event was held in Rome in 1986. Since then it has occurred in various cities throughout the world, typically every three years.

Krakow and the rest of Poland are important places of pilgrimage during the Jubilee Year of Mercy. It was in a convent chapel in Krakow where St. Faustina of the Sisters of Our Lady of Mercy received visions and messages from Jesus about his divine mercy, which she would compile in a diary that would become the book "Diary of St. Faustina: Divine Mercy in my Soul." Pope Francis is scheduled to visit the Divine Mercy Sanctuary in Krakow July 30.

In his video message, Pope Francis thanked the pilgrims for their preparation for the trip and for their prayers, and said he is looking forward to seeing pilgrims from throughout the world.

"I am very anxious to meet you and to offer the world a new sign of harmony, a mosaic of different faces, from many races, languages, peoples and cultures, but all united in the name of Jesus, who is the Face of Mercy."

He also had a particular greeting for the Polish youth upon his first visit as Pope to their country.

"For me, it is a great gift of the Lord to visit you. You are a nation that throughout its history has experienced so many trials, some particularly difficult, and has persevered through the power of faith, upheld by the maternal hands of the Virgin Mary. I am certain that my pilgrimage to the shrine of Czestochowa will immerse me in this proven faith and do me so much good," he said.

During his visit, the Pope will also symbolically present families at the event with copies of Amoris laetitia, his apostolic exhortation on love in the family.

"The moral and spiritual 'health' of a nation is seen in its families. That is why Saint John Paul II showed such great concern for engaged couples, young married couples and families. Continue along this road!" the Pope said.

World Youth Day officially kicks off July 25 and lasts through July 31, with Pope Francis arriving July 27. It will be Pope Francis' second World Youth Day during his pontificate.

The Pope closed his video by asking pilgrims to continue to pray for the event.

"Dear brothers and sisters, I send you this message as a pledge of my affection. Let us keep close to one another in prayer. I look forward to seeing you in Poland!"