As the attack on the U.S. consulate in Benghazi was unfolding, a high-ranking Pentagon official urgently messaged Secretary of State Hillary Clinton’s top deputies to offer military help, according to an email obtained by Judicial Watch.

The revelation appears to contradict testimony Defense Secretary Leon Panetta gave lawmakers in 2013, when he said there was no time to get forces to the scene in Libya, where four Americans were killed, including U.S. Ambassador to Libya Christopher Stevens.

“I just tried you on the phone but you were all in with S [apparent reference to then-Secretary of State Hillary Clinton],” reads the email, from Panetta’s chief of staff Jeremy Bash. “After consulting with General Dempsey, General Ham and the Joint Staff, we have identified the forces that could move to Benghazi. They are spinning up as we speak.”

" ... we have identified the forces that could move to Benghazi. They are spinning up as we speak.” — Jeremy Bash, Pentagon chief of staff

The email was sent out at 7:19 p.m. ET on Sept. 11, 2012, in the early stages of the eight-hour siege that also claimed the lives of Foreign Service Information Management Officer Sean Smith and two former Navy SEALs, Ty Woods and Glen Doherty, private CIA contractors who raced to the aid of embattled State Department workers.

Although the email came after the first wave of the attack at the consulate, it occurred before a mortar strike on the CIA annex killed Woods and Doherty.

“This leaves no doubt military assets were offered and ready to go, and awaiting State Department signoff, which did not come,” Judicial Watch, a nonprofit government watchdog said in a statement.

Parts of the email from Bash were redacted before release, including details on what military forces were available.

In defending the Obama administration’s lack of a military response to the attack, Panetta told the Senate Armed Services Committee nearly two years ago that “time, distance, the lack of an adequate warning, events that moved very quickly on the ground prevented a more immediate response.”

The first assault occurred at the consulate at 3:40 p.m. ET. The second attack on the CIA annex a little over a mile away began three hours later. Bash’s email was sent approximately 40 minutes after that attack began.

Bash’s email, which bore the subject line “Libya,” was sent to Clinton’s then-deputy chief of staff Jacob Sullivan, Deputy Secretary of State for Political Affairs Wendy Sherman and Deputy Secretary of State for Management and Resources Thomas Nides.

The attack came in three waves at two locations. It began when a handful of attackers scaled the wall of the diplomatic post at dusk and opened a gate, allowing dozens of armed men inside who then set the building on fire. Stevens and Smith died after breathing in smoke while hiding in a safe room, and later died.

Hours later, a nearby CIA annex was attacked twice. Woods and Doherty died there while defending the annex from the rooftop. A team of six security officials summoned from Tripoli and a Libyan military unit helped evacuate the remaining U.S. personnel who were taken to an airport and flown out of Benghazi.

The Obama administration later falsely claimed that the attack was triggered by an Internet video that insulted Islam.

Lawmakers investigating the events surrounding Benghazi already had acquired the e-mail, along with tens of thousands of others related to the probe, according to Matt Wolking, spokesman for the House Select Committee on Benghazi.

“The Select Committee has obtained and reviewed tens of thousands of documents in the course of its thorough, fact-centered investigation into the Benghazi terrorist attacks, and this information will be detailed in the final report the Committee hopes to release within the next few months," Wolking told FoxNews.com. "While the Committee does not rush to release or comment on every document it uncovers, I can confirm that we obtained the unredacted version of this email last year, in addition to Jake Sullivan’s response."