"There won't be any victorious struggle against terror, if the crises that are the causes of terrorism are not resolved", said Hollande. "This decision is irreversible", Hollande told French ambassadors at an annual meeting.
He also insisted Britain must sign-up to the EU's long list of demands for it to sign up to the single market, including freedom of movement, which Brexit backers are strongly opposed to.
"The negotiations are bogged down, positions have not been respected, and there is a clear unbalance".
"It's better to let everyone know that France will not be able to approve an accord that still lacks essential elements necessary to guarantee a positive outcome".
On Sunday, German Economy Minister Sigmar Gabriel said "in my opinion, the negotiations with the United States have de facto failed, even though nobody is really admitting it". This is reported by French President Francois Hollande, according to Reuters.
"It is more than time to stop this massacre and France is calling for an immediate truce".
He said the country's shattered second city Aleppo had endured a "large-scale humanitarian catastrophe".
However, Hollande said Turkey was now also carrying out "actions against Kurds who are themselves fighting IS with the support of the (U.S. -led) coalition".
The use of chemical weapons by the Assad regime "must be punished", he said, noting that Paris is preparing a UN Security Council resolution "to condemn these abominable acts and foresee sanctions against their perpetrators".