We are very proud: Trump hails US military for targeting Islamic State

President Donald Trump has hailed the US military's "very, very successful" strike on an Islamic State tunnel complex in Afghanistan with the largest non-nuclear bomb ever used in combat which killed 36 militants and destroyed their mountain hideouts near the Pakistan border.

In another dramatic show of military force after the bombing of a Syrian airfield with 59 Tomahawk missiles, the US military yesterday dropped a GBU-43/B, colloquially known as the "Mother Of All Bombs" or MOAB, to target tunnels and bunkers built by Islamic State fighter in Nangarhar province.

Trump said he authorised the use of the MOAB - Massive Ordnance Air Blast - and called the mission "very, very successful".

"It was really another successful job, we are very proud of our military. We are so proud of our military, it was another successful event," Trump told reporters at the White House.

The MOAB, developed for use in the Iraq war and first tested in 2003, is dropped from an aircraft on a pallet. A MOAB is a 21,600 pound, Global Positioning System (GPS)-guided munition that is US's most powerful non-nuclear bomb. Its main effect is a massive blast wave - said to stretch for 1.6 kms.

The bomb was dropped by an MC-130 aircraft, operated by the Air Force Special Operations Command. It's the first-ever combat use of the bomb, said Pentagon spokesman Adam Stump.

"Everybody knows exactly what happened, what I do is I authorise our military. We have the greatest military in the world, they've done a job, as usual, so we have given them total authorisation and that's what they're doing, and frankly, that's why they've been so successful lately," Trump said.

The bombing in Afghanistan was the second major incident when the US military in recent days have shown its combat prowess, after missile strikes on a Syrian airfield.

"If you look at what's happened over the last eight weeks and you compare that to what's happened over the last eight years, you'll see there's a tremendous difference. So we have incredible leaders of the military and incredible military, and we are very proud of them, and this was another very very successful mission," Trump said.

He, however, said he does not know if this would send a message to North Korea.

"I don't know if this sends a message. It doesn't make any difference if it does or not. North Korea is a problem.

The problem will be taken care of. I will say this: I think China has really been working very hard," he said.

White House Press Secretary Sean Spicer told reporters that the tunnels and caves IS fighters used to "move around freely" were targeted as they make it easier for them to target US military advisers and Afghan forces in the area.

"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 the US took "all precautions necessary" to prevent civilian casualties and collateral damage.

The strike was part of efforts to defeat Islamic State's local affiliate ISIS-K in Afghanistan, the US Central Command said.

Nangarhar borders Pakistan and is a hotbed of militancy.

According to the Department of Defence, there are about 600- 800 ISIS-Khorasan fighters in the area where the bomb was dropped.