Maronite Patriarch Nasrallah Sfeir warned during a meeting with French President Nicholas Sarkozy at Elysee Palace against the rapid rise in Christian emigration.
Last week, Pope Benedict XVI warned that the Christian community in the Middle East would soon disappear if no solution to regional conflicts was found.
The Pope had said that the rising political Islam and its extreme currents were a threat to Christians and Muslims alike.
Sfeir quoted Sarkozy as saying that the Christian presence in the Middle East was a "guarantee against the rise extremism."
Sarkozy, according to Sfeir, vowed to protect and support Lebanon.
"France will spare no effort to help Lebanon," Sarkozy pledged.
Sarkozy also pledged "not to leave Lebanon once again sink in a sea of differences and regional and international conflicts that loom on the horizon."