Addressing some 500 prominent figures attending the Doha conference on Tuesday, the amir said it was not enough to introduce "partial amendments to avoid criticism or ease pressure".
Reform now has "new supporters ... after only few voices pinned hopes on the birth of the era of democracy in the region", he told participants from some 50 countries at the forum's fifth edition.
Delegates at the meetings include US congressmen and European lawmakers, with France sending a 50-strong contingent.
In an address to the gathering read by Secretary of State for State Reform Eric Woerth, French President Jacques Chirac stressed that reforms must come from within, a point often made by leaders of the Gulf region.
While France encourages reform in the Arab world, "it knows that changes must come from inside and take place at the pace chosen by each of the countries of the region", he said.
"Every reform initiative must be based on the expectations and needs of states and civil societies," the French leader said.
He also said a fairer distribution of wealth was a prerequisite to stability.
"In an increasingly globalised economy, our common efforts must reconcile the requirements of political reform and economic justice," he said.