US Military's Mosul Briefing Inaccurate, Misguided: Defence Secretary Ash Carter

A U.S. military official who briefed news media about Iraq's upcoming offensive to retake Mosul provided inaccurate information but should never have publicly discussed war plans anyway, Defence Secretary Ash Carter said on Tuesday.

Carter's criticism of the February news briefing by an official from the U.S. military's Central Command was accompanied by an assurance from the top U.S. military officer to Congress that the matter was subject to an internal inquiry.

"That clearly was neither accurate information, nor had it been accurate, would have it been information that should have been blurted out to the press. So it's wrong on both scores," Carter, who took over as defence secretary in February, told a hearing by the Senate Armed Services Committee.

Two influential Republican senators on the committee, John McCain and Lindsey Graham, sent a letter to the White House on Feb. 20, complaining about the briefing, which predicted a Mosul offensive likely to start in April or May, involving 20,000 to 25,000 Iraqi and Kurdish forces.

U.S. officials, speaking to Reuters on condition of anonymity, have since suggested that timing could slip to the fall.

Mosul, which had a population of more than 1 million people, was captured by Islamic State fighters in June and is the largest city in the group's self-declared caliphate, a stretch of territory that straddles the border between northern Iraq and eastern Syria.

Carter described the briefing about the Mosul offensive as "an instance of speculation." He declined to offer a timeline, saying Iraqi forces would go into Mosul when they were ready.

General Martin Dempsey, chairman of the Joint Chiefs of Staff, said Central Command would "take the appropriate action" once the inquiry was complete.