WASHINGTON — Secretary of Defense Ashton Carter told a Senate panel that it was a “mistake” for a U.S. military official to divulge details of an Iraqi-led ground operation to retake Mosul from the Islamic State (ISIS/ISIL) in Iraq.

On Feb. 19, a U.S. Central Command (Centcom) official briefed reporters in the Pentagon, on condition of anonymity, about an upcoming ground offensive in Mosul, revealing that the U.S. wanted the Iraqi forces to launch the operation in April or May. The official, however, also noted that the offensive may take place later.

“That clearly was neither accurate information nor, had it been accurate, would have been information that should be blurted out to the press,” testified Carter before the Senate Armed Services Committee on March 3. “So it’s wrong on both scores.”

“It is important that we be open as a department — not with military secrets and not with war plans, which was the mistake made in this case — but we do try to keep the country informed of what we’re doing,” he added. “It’s about protecting them. It is a democracy. And so, openness is important but it has to have limits when it comes to security matters, and those limits obviously weren’t respected in this case.”

Jordan, a member of the U.S.-led coalition against ISIS, was furious after the anonymous Centcom official disclosed the secret location of an anti-ISIS training camp while briefing reporters.

Unnamed U.S. officials told The Wall Street Journal that the ground offensive to seize Mosul from ISIS “isn’t likely to start until the fall at the earliest, after an intensified air campaign to target Islamic State leaders and cut off supply lines in and around the city.”

It will also take “many months” to prepare Iraqi security forces to successfully retake Mosul, according to U.S. officials.

Nevertheless, Gen. Lloyd Austin, commander of Centcom, told the House Armed Services Committee on March 3 that ISIS in Iraq was losing.

“Iraqi security forces, to include Iraqi Army and Counter-Terrorism Services (CTS) forces, Kurdish Peshmerga, and tribal elements, with the support of U.S. and Coalition air operations, have halted ISIL’s advance in Iraq,” testified Gen. Austin. “The enemy is now in a ‘defensive crouch,’ and is unable to conduct major operations and seize additional territory.”

Gen. Austin told the House panel that the U.S.-led coalition has killed 8,500 ISIS jihadists in Iraq.

ISIS still controls Mosul, Iraq’s second-largest city. Retaking Mosul would mark a decisive blow against the Islamic extremist group.

ISIS jihadists captured Mosul last June, quickly defeating Iraqi government forces and eventually leading to the U.S.-led airstrike campaign in Iraq that began in August.

The February 19 press briefing was reportedly conducted by an officer at Centcom headquarters in Tampa, Florida.

According to the Associated Press, “The episode is remarkable in at least two respects. It was unusual for the U.S. military to disclose in advance the expected timing of an offensive as well as details about the makeup of the Iraqi force that would undertake it.”

It was also “curious that a secretary of defense would wait nearly two weeks after such a briefing to denounce it publicly for having spilled military secrets,” reports AP.

When reporters questioned him about it twice last weekend, Carter was cautious. “The important thing is that it will get done when it can be done successfully,” he said last Friday, referring to the Mosul operation. “And even if I knew exactly when that was going to be, I wouldn’t tell you.”

He was asked to comment again the following day. The defense secretary said it is important to keep the public informed, “consistent with security and other considerations.”

While testifying alongside Carter, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, told lawmakers that the Centcom commander is “conducting an internal inquiry” into the disclosure of details behind the Mosul operation. Gen. Dempsey added that he is confident Gen. Austin will “take the appropriate action,” without elaborating further.

The disclosure of details drew the ire of members of both parties.