The GBU-43B Massive Ordnance Air Blast bomb - better known as the "Mother Of All Bombs" - hit IS hideouts in Achin district in eastern Nangarhar province on Thursday.
President Donald Trump said Thursday the bombing was "another successful job".
The most powerful non-nuclear bomb ever used by the U.S. in combat was dropped on IS tunnels in Nangarhar province. The region where the strike took place, the restive Achin district, has for almost two years been the site of fierce fighting between the local Islamic State affiliate, known as Khorasan Province, and U.S and Afghan forces.
The explosion reverberated for miles and engulfed the remote area in towering flames, destroying what Afghan officials called a network of underground IS tunnels and caves that had been mined against conventional ground attacks.
Pakistani villagers living near the Afghan border said the explosion was so loud they thought a bomb ad been dropped in their village by USA warplanes targeting terrorists in Pakistan.
He said he's given the military "total authorization", apparently referencing actions against ISIS in general, and praised the "incredible leaders" of the military.
The bomb's destructive power, equivalent to 11 tonnes of TNT, pales in comparison with the relatively small atomic bombs dropped on Japan at the end of World War Two, which had blasts equivalent to between 15,000 and 20,000 tonnes of TNT.
According to the Department of Defence, there are about 600- 800 ISIS-Khorasan fighters in the area where the bomb was dropped.
Cancian added that while sending a message to Syria or North Korea could have been among the secondary factors considered, they would not have been the main reason for using this type of weapon.
Nangarhar Provincial Governor Gulab Mangal said IS fighters had used the complex to "kill people and hold important meetings".
Afghan officials on Thursday said they were not notified in advance that US forces would be using the bomb, but said the area had always been cleared of most of its civilian residents, and that they supported using heavy firepower against the Islamic State group.
The Massive Ordnance Air Blast bomb was dropped to reach "a system of tunnels and caves" used by the terrorists, White House press secretary Sean Spicer told reporters Thursday. It has been lovingly dubbed the Mother Of All Bombs by the United States military.
Military experts said the bomb's massive blast is terrifying and may have been meant to send a message to ISIS in Afghanistan. He said there has been heavy fighting in the area in recent weeks between Afghan forces and ISIS militants.
"I want a hundred times more bombings on this group", Hakim Khan, 50, who lives near the site of the bombing told the AP.
"The United States takes the fight against ISIS very seriously and in order to defeat the group, we must deny them operational space, which we did", Spicer said.
Experts also believe this strike could be sending a message to the Syrian regime and North Korea.
The Taliban also condemned the use of the bomb.
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.
Chief Executive of Afghanistan Abdullah Abdullah confirmed that the attack had been carried out in co-ordination with the government and that "great care had been taken to avoid civilian harm".