A U.S. soldier keeps watch from a tower at Forward Operating Base Connelly in Afghanistan’s Nangahar province on Aug. 15, 2015. (Capt. Jarrod Morris/U.S. Army)

An American service member was killed Wednesday and an unspecific number wounded while battling Islamic State loyalists in eastern Afghanistan.

Members of the Afghan army also sustained casualties in what the U.S. military characterized as a partnered operation.

Officials in Kabul have said little else about the engagement, releasing only a brief statement indicating that the wounded were evacuated for medical treatment, the families of those involved were being notified, and the mission was said to be aimed at “further reducing” the Islamic State’s regional presence.

The statement does not specify where the attack occurred, although ISIS militants are known to be active along the Pakistan border in Nangahar and Kunar provinces.

Wednesday’s fatality is the 11th suffered by U.S. forces in Afghanistan this year, surpassing last year’s total of 10. All but one resulted from hostile enemy action, according to Defense Department data. It comes, too, as the United States’ longest war nears the start of its 17th year, and the Trump administration remains without a clear strategy.

The ISIS affiliate in Afghanistan, a group known as ISIS Khorasan, or ISIS-K, is entrenched along the country’s mountainous border with Pakistan. Backed by U.S. troops and firepower, Afghan commando units have aggressively pursued its fighters for many months and shown some progress in disrupting their activity.

American and Afghan troops launched Operation Hamza in early March. The following month, U.S. forces carried out a massive airstrike on an ISIS tunnel complex in Nangarhar’s Achin district, reportedly killing upward of 100 militants. At the time, U.S. officials estimated that between 400 and 700 ISIS-K militants remained in Afghanistan.

ISIS-K is an offshoot of the terrorist group’s core network in Iraq and Syria, receiving tactical guidance and financial support from outside Afghanistan but few additional fighters.

About 14,000 U.S. and NATO troops remain in Afghanistan. With backing from the Pentagon, the war’s top commander, Army Gen. John Nicholson, wants to expand his force by about 4,000 American troops, with a match from other NATO countries.

The White House has not committed to that plan. Some advisers have suggested that contractors could gradually assume the training and advisory mission there, allowing U.S. troops to come home.

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