Attorneys for the victims of the 2009 Fort Hood massacre said that the alleged shooter's admission this week that he gunned down his countrymen to defend the Taliban proves that the assault was a terrorist attack and not, as the government has implied, "workplace violence."

Accused gunman Maj. Nidal Hasan announced the revelation Tuesday as he asked the court for a delay in his trial so he could prepare a new "in defense of others" legal strategy.

When Judge Col. Tara Osborn asked specifically who he was defending, Hasan said, "The leadership of the Islamic Emirate of Afghanistan, the Taliban" and its leader Mullah Omar, according to an account by The New York Times.

Thirteen people were killed and another 32 were injured when Hasan allegedly opened fire on his fellow soldiers at the Texas Army facility in November 2009. Hasan said Tuesday the troops were about to deploy to Afghanistan where they would pose an immediate danger to the Taliban.

Prior to Tuesday's admission, and despite evidence showing Hasan had been in communication with high-profile al Qaeda cleric Anwar al-Awlaki, survivors of the tragedy said they have been denied Purple Hearts and certain combat-related medical benefits because the government refuses to classify the shooting as a terrorist act. Instead, several government documents that discuss the attack refer to efforts to combat "workplace violence."

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The Defense Department has maintained that there is not sufficient evidence to prove the incident was a terrorist attack and has expressed concern that a premature designation would interfere with Hasan's ability to receive a fair trial.

"However, now the government's 'workplace violence' lie has been fully exposed," said Neal Sher and Reed Rubinstein, legal representatives for the Fort Hood victims and their families. "By his own admission, Hasan was a jihadist who killed innocent Americans to defend the Taliban."

"We call on the Army to… admit that the Fort Hood attack was terrorism; and finally provide the Fort Hood victims, survivors and families with all available combat-related benefits, decorations and recognition," they said.

Mullah Omar, the one-eyed Taliban chief, has been a longtime member of the State Department's wanted terrorist list, with $10 million offered for information leading to his location.

Judge Osborn postponed a ruling Tuesday on Hasan's request for a trial delay but called for another hearing today. If convicted, Hasan could face the death penalty or life without parole.

ABC News' Ned Berkowitz and The Associated Press contributed to this report.