An Afghan military officer who deserted last month while participating in a training program in the U.S. was arrested on a Washington-state bound Amtrak train, U.S. Border Patrol agents said Thursday.

Mustafa Tanin was arrested Tuesday when the train stopped to refuel in Havre, Montana. Border Patrol agents had boarded the train in search of somebody else when they came across Tanin and questioned him, Agent Craig Duff said.

"He initially claimed to be from Mongolia," Duff said. "During questioning, he admitted to being from Afghanistan."

Border Patrol agents found an identification document on Tanin and discovered that his U.S. visa had been canceled because he had deserted, Border Patrol Agent Melissa Hart said.

Tanin, a lieutenant in the Afghan Army, arrived in the U.S. in May for a Basic American Language Instructor Course at Lackland Air Force Base in San Antonio, Texas. The program is for military personnel and civilians to improve their English and prepare them to teach the language in their countries, said Air Force Maj. Toni Whaley.

Tanin failed to report for activities during a weeklong field study in Washington, D.C. He was declared an international military student absent without leave by the head of the Defense Language Institute English Language Center on Sept. 25, Whaley said.

Tanin did not give a reason for leaving the training, did not ask for political asylum and did not resist arrest, Duff said.

Duff said a second another Afghan military official deserted with Tanin, though Whaley said Tanin was the only person who failed to report.

"While there have been others who have absconded while in training, there is a well-coordinated process among federal agencies to locate the individuals as quickly as possible and return them to their respective homeland," Whaley said.

U.S. Immigration and Customs Enforcement officials were holding Tanin in Great Falls. He will be transported to Salt Lake City, where he will face deportation proceedings, Border Patrol Agent Melissa Hart said.

Last September, three Afghan military officers who were participating in a joint military training exercise in Cape Cod, Massachusetts, were detained after they crossed the Canadian border at Niagara Falls to seek refugee status.

They said they feared retribution by the Taliban because of their work with U.S. soldiers.

Canada denied the men entry and returned them to the U.S., which began deportation proceedings against them. One of the three was later allowed to make a refugee claim in Canada.