He also called for "concrete actions" from the international community during his first general audience since he underwent intestinal surgery a month ago.
Francis said many in Lebanon, which is mired in a financial depression and faces its worst social crisis in 30 years, had lost "even the illusion of living."
Last year's huge chemical explosion in Beirut killed 200 people and caused billions of dollars worth of damage.
The Vatican's foreign minister, Archbishop Paul Gallagher, said last month the visit could take place late this year or early next year.
He suggested the pope could go even without a government in place.