Over 6,000 ISIS fighters were believed to have been killed by US-led airstrikes in Iraq. The claim was announced Thursday by the diplomatic official of the United States. It was also reported that half of the Islamic State's top commanders had also been killed by the US offensives.

In an interview with Al Arabiya News, US Ambassador to Iraq Stuart Jones announced that the US-led coalition airstrikes have killed an estimate of more than 6,000 ISIS fighters in Syria and Iraq. He also added the bombings have destroyed over a thousand ISIS vehicle inside Iraq.

After Baghdad criticized the White House for its insufficient efforts to eliminate the Islamic State terrorists, Jones described the airstrikes of having a "devastating" effect on ISIS command. However, since doubts were casted over Jihadi John's identity, it can't be avoided that these recent claims were also questioned. So are these claims really true or are just another exaggerated brag?

At a coalition meeting in London, which was attended by Iraqi Prime Minister Haider al-Abadi and other officials from 21 nations, PBS Frontline reported US Secretary of State John Kerry announced that the US-led airstrikes have killed 50 percent of the top commanders of the ISIS militants.

The 6,000 ISIS fighters killed estimate was calculated the US Central Command (CENTCOM). The agency has been keeping tabs of the number of fighters killed, but has not made the information public.

The Western intelligence agencies has assessed the ISIS' total force to be somewhere between 9,000 to 18,000 fighters. However, CNN revealed that it is also believed the extremists can draw on thousands of other insurgents whose loyalty shifts and could gather a total force of up to 31,000.        

Although the officials have announced that over 6,000 ISIS fighters have been killed by the US-led coalition offensives, Defense Secretary Chuck Hagel would confirm the number of deaths, instead he would just say "thousands" have perished. And when asked whether the body count is an indication of development, Hagel stated that "it's a measure but I don't think it's the measure."

So far, the Pentagon has avoided discussing the issue. The only information that was disclosed was the estimate of 6,000 ISIS fighters may have been killed. CBS News reported the announcement came after US President Barack Obama pledged to work with Congress on a new authorization for military action against ISIS during his annual State of the Union address on Tuesday.