Spokeswoman Capt. Elizabeth Mathias said the soldier disappeared Tuesday.
“We understand him to be have been captured by militant forces. We have all available resources out there looking for him and hopefully providing for his safe return,” Mathias said.
Mathias did not provide details on the soldier, the location where he was captured or the circumstances.
The news broke as thousands of U.S. Marines launched a major anti-Taliban offensive in southern Afghanistan. The missing soldier was not part of that operation.
“We are not providing further details to protect the soldier’s well-being,” she said.
Afghan Police Gen. Nabi Mullakheil said the soldier went missing in the Mullakheil area of eastern Paktika province, where there is an American base.
The missing man is an enlisted soldier, and his family has been notified.
Zabiullah Mujaheed, a spokesman for the Taliban, could not confirm that the soldier was with any of their forces. A myriad of insurgent groups operate in eastern Afghanistan, and the Taliban is only one of them.
The most important insurgent group operating in that area is known as Haqqani network and is led by Siraj Haqqani, whom the U.S. has accused of masterminding beheadings and suicide bombings.
writer Pauline Jelinek in Washington contributed to this report.
