The GBU-43 Massive Ordnance Air Blast (MOAB) had been dubbed "the mother of all bombs".
The pontiff recently told an audience of students that the word "mother" should not be used in reference to a deadly weapon.
He said: "I was ashamed when I heard the name.
"A mother gives life and this one gives death, and we call this device a mother. What is happening?"
The US Air Force dropped the bomb on suspected Islamic State of Iraq and the Levant (ISIL) fighters in Afghanistan last month.
The bomb weighs 10kg and has a mile wide radius.
Pope Francis is set to meet US President Donald Trump on in a few weeks. They have opposing views on a number of issues including immigration, climate change and the refugee crisis.
