But, he said, "it will be up to you and your armed forces to demonstrate that the G5 can be effective while respecting humanitarian conventions".
The 5,000-strong force will be deployed by September, and its funding will be finalized by then, Macron said at a press conference.
"We can not hide behind words, and must take actions", Macron said as he expressed the hope the force would be operational within weeks.
The coalition force is to tackle jihadist bombings, shootings and kidnappings in the Sahel region - between the Sahara to the north and the Sudan region towards the east.
He is hoping that the 50 million euros promised to the Sahel force by the European Union will be supplemented by extra support from Germany, the Netherlands, Belgium and the United States.
"Every day we must combat terrorists, thugs, murderers.who we must steadfastly and with determination eradicate together", he said.
Deby and Macron also discussed the financial issue on the sidelines of the Bamako summit, with the French and Malian leaders both saying the Chadian president had been reassured by the talks.
The new Sahel force will support national armies trying to catch jihadists across porous frontiers, and its operations will be closely coordinated with Barkhane, a source in the French presidency told AFP. A French-led intervention drove out Islamic extremists from strongholds in northern Mali in 2013, but the extremists have continued targeting peacekeepers and other forces. Chad's military is considered the strongest among the Sahel forces.
The leaders of Mali, Mauritania, Niger, Burkina Faso and Chad known as the G5 must clarify their roles and contributions for the force to attract more support from outside countries, the French president added.