American bombers deployed one of the largest, non-nuclear munitions in the U.S. arsenal on an Islamic State tunnel complex in eastern Afghanistan for the first time, possibly indicating an uptick in operations against the terror group’s faction in the country.

An MC-130 Combat Talon assigned to U.S. Air Force Special Operations Command dropped a GBU-43, known as the “mother of all bombs,” Thursday on the tunnel complex in the Achin district in eastern Afghanistan’s Nangahar province, which is home to Afghan Islamic State faction, known as Islamic State in Iraq and Syria-Khorasan province, or ISIS-K.

“The strike was designed to minimize the risk to Afghan and U.S. Forces conducting clearing operations in the area while maximizing the destruction of ISIS-K fighters and facilities,” according to a statement from U.S. Forces-Afghanistan.

The attack comes as President Trump announced Wednesday that National Security Adviser H.M. McMaster would be heading to Afghanistan, to assess the current state of U.S. operations in the country. Since his stunning electoral in last November, Mr. Trump and his national security team have been mum on the way ahead for the U.S. mission in Afghanistan.

The last visit by a sitting national security adviser to the country was in 2009. Then-President Barack Obama sent then National Security Adviser Jim Jones to Afghanistan, shortly before announcing his surge strategy for the country. Washington officially ended combat operations there in 2014, taking on a train-and-advise mission shortly thereafter.

At 22,000 pounds with a blast yield equivalent to 11 tons of TNT, the bomb was initially built to destroy heavily fortified underground enemy bunkers. It is the most powerful conventional weapon in the U.S. armory.

The decision to use the devastating weapon during the Achin airstrike was necessary, given the increased threat of ISIS-K to Afghan, U.S. and NATO forces in the country, the top U.S. commander in Afghanistan said.

“As ISIS-K’s losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defense,” Gen. John Nicholson said in a command statement.

“This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K,” he added, noting that U.S. forces will proceed with such operations “until ISIS-K is destroyed in Afghanistan.”