Speaking after talks in Rome, US Secretary of State John Kerry said 10,000 airstrikes in the year since the coalition was launched had yielded "undeniable progress" with IS forced to give up 40 per cent of the territory it once controlled in Iraq and more than 30 per cent in Syria.
Kerry said he was confident that promises made today would lead to a "very substantial amount of money" being pledged at a donor conference for Syria in London on Thursday.
Kerry said the coalition had helped train 10,000 Iraqi and Peshmerga soldiers to fight IS as well as 1,000 Iraqi police.
IS had been forced to cut its fighters' salaries and reduce weapons purchases thanks to coalition moves to cut off its financing and access to oil.
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"Unequivocably, together with our allies on the ground, we are pushing Daesh out of territories it once controllled," Kerry said.
In a joint statement, the coalition ministers said: "We will intensify and accelerate the campaign against ISIL/Daesh in Iraq and Syria, act in concert to curb its global ambitions, and take every measure to ensure the protection of our citizens.
"We reaffirm our commitment to deliver a lasting defeat to this barbaric organisation."
The statement expressed concern over "the growing influence" of IS in Libya but stopped short of threatening air strikes there.
It said only that the allies would "continue to monitor closely developments there, and stand ready to support" a proposed national unity government that is struggling to establish itself.