Macron on Thursday became the first world leader to visit Beirut after Tuesday's explosion.
He warned Lebanese leaders that while international aid would be forthcoming, deep change was needed to resolve the country's problems.
The blast at the Beirut port, blamed on a vast store of ammonium nitrate that was allowed to rot for years in a warehouse, destroyed entire neighbourhoods.
It killed at least 158 people and more than 6,000 others were injured, but numbers are expected to rise as search and rescue operations continue for missing people.