“I can't talk to the rate of replenishment, and I actually do not a sound figure myself on the number of forces that [ISIL] is fielding right now in Iraq and Syria,” Killea, Combined Joint Task Force-Operation Inherent Resolve Chief of Staff, told the briefing on Friday, according to a Department of Defense transcript.
Killea acknowledged he would have to defer that question to the US Central Command J2 Intelligence section.
“In my opinion, in my position, I should say, the only thing I can tell you with confidence is the effects that I'm seeing on the battlefield,” Killea added.
Earlier in 2015, the US intelligence community estimated that Islamic State combat strength in Iraq and Syria to from 22,000 to 32,000 fighters, but the figure has been slightly reduced from 20,000 to 30,000 in an estimate released to the press this week.
The US-led 62-nation coalition began carrying out airstrikes against the ISIL in Iraq in August 2014, and expanded the air campaign to Syria in September 2014, but without Syrian government approval. The coalition has conducted more than 5200 airstrikes on ISIL targets.
