In an interview with Al Jazeera TV, Karzai said the US government had allowed Daesh to flourish inside Afghanistan .
"In my view under the full presence, surveillance, military, political, intelligence, Daesh [ISIL] has emerged," he said. "And for two years the Afghan people came, cried loud about their suffering, of violations. Nothing was done."
According to Karzai, the US administration under President Donald Trump made Daesh an excuse to drop a massive bomb in Afghanistan on April 2017. But, Karzai said, the very next day Daesh took over another district of Afghanistan .
"That proves to us that there is a hand in it and that hand can be no one else but them [the US] in Afghanistan ."
GBU-43, the largest non-nuclear bomb, the US used in combat was dropped in the Achin district of Nangarhar province, close to the border with Pakistan, reportedly killing at least 36 Daesh fighters and destroying tunnel complex of the armed group.
The US Central Command said the strike was designed to minimise the risk to Afghan and US forces conducting clearing operations in the area.
The explosive also known as the mother of all bombs was equal to 11 tonnes of TNT (trinitrotoluene) with a blast radius of 1.6 kilometres. Witnesses said they felt the ground shake after the explosion while others described towering flames in the aftermath.
At that time, Karzai also condemned the attack calling it an inhumane act and most brutal misuse of Afghanistan as testing ground for new and dangerous weapons .