US Service Member Killed by IED in Afghanistan

A U.S. service member has died from wounds sustained today in an operation near Lashkar Gar in Helmand Province, Afghanistan, the Pentagon confirmed.

The service member was conducting "train, advise, assist" activities with Afghan counterparts when the patrol "triggered an improvised explosive device," or IED, according to a news release from U.S. Forces Afghanistan.

The Pentagon has not released the service member's name because of next-of-kin notification.

Another U.S. service member and six Afghan soldiers sustained wounds during the operation.

"On behalf of all of U.S. Forces - Afghanistan, as well as Resolute Support, our deepest sympathies go out to the families and friends of those involved," Gen. John W. Nicholson, commander of U.S. Forces Afghanistan and Resolute Support, said in the news release. "We are deeply saddened by this loss, but remain committed to helping our Afghan partners provide a brighter future for themselves and their children."

This is the second U.S. combat death in Afghanistan this year. In January, Army Green Beret Staff Sgt. Matthew McClintock, 30, died after an hours-long firefight near Marjah in Helmand Province. McClintock was assisting Afghan Special Operations troops as they defended against an intense Taliban assault.

The Pentagon confirmed Monday that a force of 100 U.S. troops had been sent to Lashkar Gar to train, advise, and assist the local Afghan police force as they face a major summer offensive by the Taliban. That group included trainers, as well as the force that would provide security and force protection for them.

In Monday's briefing, Pentagon Press Secretary Peter Cook told reporters the force would not be a permanent presence, and that the troops would "return to their base at some point."

There is a force of several hundred other U.S. personnel at the former Camp Bastion in Helmand Province that has been training the Afghan Army.

When pressed on the progress made in Helmand Province, Cook said that the Afghan forces had shown "resiliency" in recent months, and the decision to send additional U.S. forces to Lashkar Gar reflected U.S. support.

But Cook also warned that "there still are challenges in Afghanistan."

"There are going to be setbacks along the way," Cook said, later adding, "certainly,there's room for improvement."

ABC News' Luis Martinez contributed to this report.