"We have seen a lot of losses within Daesh since the start of this campaign, more than 10,000," Blinken said on France Inter radio, using the Arabic acronym for ISIS.

"It will end up having an impact."

Blinken was speaking after the coalition made up of Western and Arab states met in Paris, he said there had been a great deal of progress in the fight against Islamic State but that the group remained resilient and capable of taking the initiative.

"At the start of this campaign (we) said it would take time," he said. "We have conceived a three-year plan and we're nine months into it."

Iraq's Prime Minister on Tuesday accused the international coalition fighting ISIS of not doing enough to tackle the militant group, and said key members like Saudi Arabia are not curbing the flow of foreign fighters to his country.

The meeting follows the Iraqi government's biggest military setback in nearly a year. On May 17, ISIS seized Ramadi from the demoralized and disordered Iraqi army. The city is just 90 km west of Baghdad and the capital of the overwhelmingly Sunni Anbar province.