A U.S. service member was killed "in action" in Afghanistan on Saturday, the Pentagon announced in a brief statement.

The identity of the service member is being withheld for 24 hours until after the next of kin has been notified, following military policy. The circumstances surrounding the death are not immediately known, but according to Taliban spokesman Zabihullah Mujahed, the militant group has claimed responsibility.

Peace talks to end the 18-year war in Afghanistan have been underway, but the Taliban has recently increased hostilities. An attack earlier this month in Kabul resulted in the deaths of dozens, including many children.

The killing on Saturday marks the fourth death of a U.S. service member in Afghanistan within a month. Sgt. 1st Class Elliott Robbins, Master Sgt. Micheal Riley, and Sgt. James Johnston all died in Afghanistan over the past few weeks. Eleven service members have been killed in Afghanistan this year.