Paris - Organizers expect around 200,000 people to participate in a open-air mass celebrated by Pope Benedict XVI at on Saturday.

The 81-year-old pontiff will celebrate mass at Esplanade des Invalides park.

The pope will then travel to the pilgrimage site of Lourdes in southern France. The Catholic Church this year celebrates the 150th anniversary of the apparition of the Virgin Mary to a 14-year-old peasant girl, Bernadette Soubirous, in 1858.

French President Nicolas Sarkozy and his wife Carla Bruni-Sarkozy welcomed the pope on Friday at the Elysee Palace. In a speech to about 700 intellectuals the same day Benedict XVI discussed the Christian roots of European culture and lamented the secularisation of society.

In the evening, he adressed 10,000 young people in front of Notre Dame Cathedral.

The pope is on a four-day visit to France, trying to revive Catholicism in the fiercely secular country. (dpa)