KABUL, Afghanistan >> Former Afghan President Hamid Karzai said today that the U.S. is using Afghanistan as a weapons testing ground, calling the recent use of the largest-ever non-nuclear bomb “an immense atrocity against the Afghan people.”

Last week, U.S. forces dropped the GBU-43 Massive Ordnance Air Blast (MOAB) bomb in eastern Nangarhar province, reportedly killing 95 militants. Karzai, in an interview with The Associated Press, objected to the decision, saying that his country “was used very disrespectfully by the U.S. to test its weapons of mass destruction.”

The office of President Ashraf Ghani said following the bomb’s usage that there was “close coordination” between the U.S. military and the Afghan government over the operation, and they were careful to prevent any civilian casualties.

But Karzai harshly criticized the Afghan government for allowing the use of the bomb.

“How could a government of a country allow the use of a weapon of mass destruction on its own territory? Whatever the reason, whatever the cause, how could they allow that? It just unimaginable,” he said.

The strike was carried out Thursday morning against an Islamic State group tunnel complex, carved into a mountain that Afghan forces had tried to assault repeatedly in recent weeks, according to Afghan officials.

U.S. and Afghan forces have been battling the Taliban for more than 15 years. But the U.S. military unveiled the largest conventional bomb in its arsenal against the Islamic State group, which has a far smaller but growing presence in Afghanistan. U.S. President Donald Trump has publicly vowed to aggressively confront IS.

Trump called the operation a “very, very successful mission” but Karzai had harsh words for the new U.S. leader.

“My message to President Trump today is that he has committed an immense atrocity against the Afghan people, against fellow human beings,” he said. “If the American government sees us as human beings, then they have committed a crime against fellow human beings, but if they treat us as less than human beings, well, of course they can do whatever they want.”

Karzai added that one of the fundamental reasons that he refused to sign the bilateral security agreement with the United States when he was the president was specifically to prevent such actions.

“I told the people of Afghanistan in the Loya Jirga (Grand Assembly) we must not sign the BSA with the U.S., that we must not give them bases till the day they bring peace to Afghanistan,” he said. “Why would the Afghan people want to give the U.S. bases? For what? To continue the war in Afghanistan, to become more insecure, to lose peace forever, to suffer, to receive more bombs, to receive a weapon of mass destruction? Or for security, for peace and for a better life?”

The U.S. National Security Adviser H. R. McMaster met with President Ghani during a visit to Afghanistan on Sunday. According to statement from the office of the president, the pair discussed mutual counterterrorism efforts, security and economic development.

The U.S. estimates 600-800 IS fighters are in Afghanistan, mostly in Nangarhar. American forces have concentrated on fighting them while also supporting Afghan forces against the Taliban. The U.S. has more than 8,000 troops on the ground in Afghanistan, training local forces and conducting counterterrorism operations.