KABUL: Two US service members were killed during an operation against Daesh militants in eastern Afghanistan overnight on Wednesday, US officials said on Thursday, as President Donald Trump's administration looks to craft a strategy in the war-torn country.

US forces in Afghanistan said in a statement that a third US service member was wounded in the raid, carried out with Afghan National Defense and Security Forces (ANDSF) against the militants.

A spokesman for the US military in Afghanistan, Captain William Salvin said the deaths occurred in the same valley where the United States had dropped a massive bomb on a complex of fortified tunnel being used by Daesh.

Nicknamed "the mother of all bombs," the GBU-43 Massive Ordnance Air Blast bomb was dropped from an American MC-130 aircraft in the Achin district of Nangarhar province, bordering Pakistan.

The incident comes just days after US Defense Secretary Jim Mattis visited Afghanistan and US troops are battling suspected Daesh militants in Nangarhar province.

In this raid, Afghan commandos and coalition forces killed some 40 Daesh fighters during a joint operation, said Attahullah Khogyani, a spokesman for the Nangarhar governor.

Khogyani said the raid was carried out against a Daesh hideout in Achin district and some 13 militants were taken alive.

Another US soldier was killed earlier in April while carrying out operations against Daesh in the same province.

US officials say intelligence suggests Daesh is based overwhelmingly in Nangarhar and neighboring Kunar province.

Estimates of its strength in Afghanistan vary. US officials have said they believe the movement has only 700 fighters but Afghan officials estimate it has about 1,500.