Kabul, Afghanistan (CNN) -- The U.S. Defense Department on Monday identified the SEAL killed during a successful raid to free a captive doctor in Afghanistan.

Petty Officer 1st Class Nicolas D. Checque, 28, of Monroeville, Pennsylvania, died Saturday during the effort to free Dr. Dilip Joseph, the Navy said. NATO commanders believed Joseph was in imminent danger from his captors when the raid took place.

While the Defense Department announcement said only that Checque belonged to an "East Coast-based Special Warfare Unit," a U.S. official said the man was a member of the Navy's Special Warfare Development Group, more commonly known as SEAL Team Six. The elite unit is the same one that took part in the raid that killed al Qaeda leader Osama bin Laden.

The official didn't know if the SEAL who died was involved in that operation.

"He gave his life for his fellow Americans, and he and his teammates remind us once more of the selfless service that allows our nation to stay strong, safe and free," President Barack Obama said of the slain SEAL before his identity was made public.

Armed men kidnapped Joseph and two other staff members for the international aid group Morning Star on Wednesday as they returned from a rural medical clinic in eastern Kabul province.

Tribal leader Malik Samad and district chief Muhammad Haqbeen told CNN that Joseph and an Afghan doctor were abducted near the village of Jegdalek in the Sarobi district, just outside Kabul.

The International Security Assistance Force said Taliban insurgents kidnapped the men. Samad and Haqbeen identified the kidnappers as smugglers.

Morning Star said negotiations began "almost immediately" with the captors and went on sporadically into Saturday night, when two of the three were released.

The Afghan doctor's family paid $12,000 to the smugglers, Haqbeen and Samad said. Morning Star denied paying any "ransom, money or other consideration" to win the release of its staffers, and the raid to free Joseph came 11 hours later after the other two were released.

U.S. officials provided few details about the rescue effort, but Secretary of
Defense Leon Panetta said the SEALs "knew they were putting their lives on the line to free a fellow American from the enemy's grip."

Checque joined the Navy in 2002, according to a brief service record provided by the Defense Department. After attending recruit training in Illinois and advanced training in Virginia, he entered the seal program in April 2003.

He was assigned to his first SEAL unit in August 2004, and transferred to a second unit, presumably SEAL Team Six, in September 2008.

He received the Bronze Star and several other awards during his 10-year Naval career.

The rescued doctor, Joseph, has worked with Morning Star for three years. He serves as its medical adviser, and travels frequently to Afghanistan, the agency said.

Morning Star did not release the identities of the other two men, citing safety
concerns.

Joseph is expected to return home to Colorado Springs, Colorado, within a few days, after medical examinations and debriefings, the agency sad.

On Sunday, his family extended condolences to the slain sailor's family.

"We are incredibly grateful for the multiple agencies of the U.S. government that have supported us in this difficult time, and especially the quick response by our military and partner allies to rescue Dilip," the family said. "They showed great heroism and professionalism."

Despite the kidnappings of Joseph and its two other staffers, Morning Star
reiterated its "commitment to continue its work" in Afghanistan.

Navy SEAL Killed While Rescuing Doctor