Airstrikes have killed 10,000 ISIS fighters?

via NBC

A top U.S. diplomat strayed from a long-held wartime taboo Wednesday when he reported that 10,000 ISIS militants had been killed in Iraq and Syria, raising questions about how that number was compiled and whether it accurately reflected a U.S.-led coalition's success against the Islamic terror group.
"We have seen a lot of losses within Daesh since the start of this campaign, more than 10,000," Deputy Secretary of State Antony Blinken said on France Inter radio, using an alternate name for ISIS. "It will end up having an impact."

Here.

Wow.  The Pentagon really went there?  They're attempting to do body counts on a fluid battlefield?

Amazing....and bullshit.

If this were true then ISIS would be on the verge of ceasing to exist.  Additionally  we wouldn't be seeing the offensive that they've started.

Why are they telling outright lies now?