The US army has confirmed an aspect of surveillance whistleblower Edward Snowden's military service to the Guardian.

As Snowden told the Guardian in announcing his responsibility for detailing multiple mass surveillance efforts by the National Security Agency sweeping up Americans' communications data, he indeed tried to join the elite special forces.

His attempt was unsuccessful.

"His records indicate he enlisted in the army reserve as a special forces recruit (18X) on 7 May 2004 but was discharged 28 September 2004," the US army's chief civilian spokesman, George Wright, said by email on Monday. (In his Guardian interview, Snowden gave the year as 2003.)

"He did not complete any training or receive any awards," Wright added.

The army did not release Snowden's entire service record, a form known as a DD-214, despite the Guardian's request. A DD-214 typically details a military service member's entire career history, such as locations of his or her billets, job responsibilities and honorable or dishonorable discharges – none of which the army disclosed on Monday. Nor did the army explain the reason for Snowden's incomplete special forces recruitment.

Typically, so-called 18X candidates are approved to try out for a position in the army special forces, often after passing a vocational aptitude test, but selection to the elite cadre is never guaranteed. Training is a rigorous physical and mental challenge lasting 14 weeks.

The Guardian reported, citing Snowden, that his military career was cut short after "he broke both his legs in a training accident."

The army did confirm Snowden's date of birth: June 21, 1983.