“Great floods have sown grief and devastation in various regions of Mozambique, Zimbabwe and Malawi,” he said, addressing thousands of the faithful in Saint Peter’s Square.
“To those dear people I express my pain and my closeness,” he added.
“I entrust the many victims and their families to the mercy of God and I implore comfort and support for those affected by this calamity.”
The death toll from the cyclone that hit last week has topped 300 people, and rescue teams are still trying to reach survivors forced to take refuge from rising floodwaters on the roofs of buildings and in trees.
The United Nations says that one of the worst storms to hit the region in decades has also unleashed a humanitarian crisis in Malawi, affecting nearly a million people and forcing more than 80,000 from their homes.
Pope Francis may visit Mozambique during a tour to Africa in September.