The target was an ISIS tunnel and cave complex in Afghanistan.
The use of the bomb, now confirmed in the US, is the first time EVER.
The GBU-43 bomb weighs 21,600 pounds, is 30 feet long and contains 11 tons of explosives.
Trump’s spokesman Sean Spicer said the US is taking the threat from ISIS “very seriously”.
He said: “In order to defeat the group we must deny them operational space. Which we did.
“The United States took all precautions necessary to prevent civilian casualties and collateral damage as a result of the operation.”
Sources said the bomb dropped is known as an MOAB – mother of all bombs.
The blast radius is believed to be over 300 meters.
The blast zone could stretch up to 300m – military experts say (stock image)
The Pentagon has confirmed the blast happened in Afghanistan's Nangarhar – and the giant weaponry was used.
The bomb, known as the GBU-43B, is a 21,000 lb giant and was developed during the Iraq war.
General John Nicholson, commander of US forces in Afghanistan, signed off on the use of the bomb, according to CNN sources.
The ginormous missile was too big to release from traditional bomb-bay door or release from an aircraft wing so it was “kicked it out the back door,” an official revealed.
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ISIS jihadis are believed to have been taken out.
Map of the area of Afghanistan where the Mother of All Bombs was blasted
The bomb was dropped at 7pm local time on Thursday, the sources said.
It is specialist GPS-guided munition which can cause devastation on the ground.
The bomb was dropped by an MC-130 aircraft directly onto ISIS tunnels and personnel in the Achin district.
The damage is being assessed.
Mr Spicer told reporters MOAB is 'a large, powerful and accurately delivered weapon’.
He said its mission was to collapse tunnnels used by ISIS terrorists.
The 'mother of all bombs' MOAB dropped in Afghanistan (stock image)
The massive ordnance was tested in at the Eglin Air Force Base, Florida in 2003.
Jihadis fighting for the Islamic State, also known as daesh, are renowned for their huge underground tunnels used in Irar and Syria.
Sneaking around under the city of Mosul the jihadis have been able to pop up on Iraqi forces.
However, their tunnels, some big enough to drive cars in, and fitted with air-con and stacked with food, have not been enough to beat coalition-backed forces.
The tunnels usually begin inside an abandoned home or business and can stretch for miles.
The huge US bomb drop comes one week after Trump stole global headlines when he dropped a bomb in Idlib, Syria.
He was relating to a chemical gas attack on children and families in the region.
Donald Trump vowed to continue his war against ISIS with Nato chief Jens Stoltenberg
President Assad denied the horror – after videos and images flooded the internet and newsrooms around the world.
Trump made the decision to take out the airbase planes fly out of when conducting operations for Assad.
The move infuriated Russia who have backed the murderous Assad regime.
Shocking photographs show ISIS wreak havoc in Iraq
Thu, February 2, 2017
Inside Islamic State’s arsenal: Jihadis using HELL CANNON in northern Iraq and MAKING bombs on INDUSTRIAL SCALE in these shocking photographs.
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Tensions between Moscow and Washington continue to run high.
However, Donald Trump is continuing with his personal “war on terror”.
Mr Trump vowed only yesterday to attack ISIS when he met with General Secretary on the Nato Jens Stoltenberg.