France has around 4,500 troops taking part in Operation Barkhane, which is combating militants in Chad, Mauritania, Mali, Burkina Faso and Niger.
Macron addressed some 1,000 soldiers in the capital N’Djamena, telling them to work on the establishment of a regional anti-terrorism force made up of the so-called G5 countries.
“The coming months will be decisive,” he said.
Macron also praised the “exemplary co-operation” between France and the United States, and with some of his country’s allies also active in the region - Britain, Spain, Germany and Estonia.
At an earlier meeting with Burkina Faso President Roch Marc Christian Kabore in Paris, Macron reaffirmed his support for the Sahel countries.
“We will remain active alongside the Sahel nations, until the victory is complete,” Macron said.
Chad is engaged in fights against terrorism on several fronts.
The Boko Haram terror group is active around Lake Chad, near the country’s border with Nigeria.