In an interview with the BBC, Abadi said there were enough fighters on the ground but they needed arms and equipment to defeat the jihadists.
"I was a bit frustrated in my first three months of being a prime minister because of the slowness of this support but I've seen in the last probably four weeks, five weeks, there is an acceleration of the support," Abadi added.
"I think the air bombing and the air campaign has increased in its intensity and its quality."
The international air campaign against the IS group was launched in Iraq in August and expanded to Syria the following month.
There have been over 2,000 air strikes on IS so far.