Afghanistan officials said 36 Islamic State militants were killed when the U.S. dropped the “mother of all bombs” on a tunnel complex Thursday.

The Afghanistan Ministry of Defense added in a statement Friday that there were no civilian casualties and that several Islamic State caves and ammunition caches were destroyed.

The GBU-43B, a 21,000-pound conventional bomb, was deployed in Nangarhar Province close to the Afghanistan/Pakistan border. The MOAB -- Massive Ordnance Air Blast -- is also known as the “Mother Of All Bombs.” It was first tested in 2003, but hadn't been used in combat before Thursday.

President Trump told media Thursday afternoon that "this was another successful mission" and he gave the military total authorization.

Pentagon spokesman Adam Stump said the bomb had been brought to Afghanistan "some time ago" for potential use. The bomb explodes in the air, creating air pressure that can make tunnels and other structures collapse. It can be used at the start of an offensive to soften up the enemy, weakening both its infrastructure and morale.

"As [ISIS'] losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defense," Gen. John Nicholson, commander of U.S. forces in Afghanistan, said in a statement. "This is the right munition to reduce these obstacles and maintain the momentum of our offensive against [ISIS]."

The MOAB had to be dropped out of the back of a U.S. Air Force C-130 cargo plane due to its massive size.

"We kicked it out the back door," one U.S. official told Fox News.

Ismail Shinwari, the governor of Achin district, said the U.S. attack was carried out in a remote mountainous area with no civilian homes nearby. He said there has been heavy fighting in the area in recent weeks between Afghan forces and ISIS militants.

Hakim Khan, 50, a resident of Achin district where the attack took place, welcomed the attack on ISIS, saying: "I want 100 times more bombings on this group."

The strike came just days after a Green Beret was killed fighting ISIS in Nangarhar, however, a U.S. defense official told Fox News the bombing had nothing to do with that casualty.

“It was the right weapon for the right target, and not in retaliation,” the official said.

The U.S. estimates that between 600 to 800 ISIS fighters are present in Afghanistan, mostly in Nangarhar. The U.S. has concentrated heavily on combatting them while also supporting Afghan forces battling the Taliban.

In August, a company of nearly 150 Army Rangers killed "hundreds" of ISIS fighters in Nangarhar, though five of the Rangers were shot. Some weapons and equipment, including communications gear and a rocket launcher, were also left behind following the operation.

Fox News’ Lucas Tomlinson and the Associated Press contributed to this report.