WASHINGTON — The commanding general of the war in Afghanistan has ordered the U.S military there to wait to announce when an American service member has died until days after the incident, breaking with a policy that dates back to Vietnam.

Since the U.S. invasion in 2001, when a U.S. service member is killed in Afghanistan, the military command in Kabul makes the first announcement. This initial release is generally devoid of much specific information, usually identifying the area and basic information about the incident, but withholding the name and any personal information about the deceased individual.

Identification of the individual is withheld because of a 2009 Pentagon policy stating that "no casualty information on deceased military or DoD civilian personnel may be released to the media or the general public until 24 hours after notifying the [next of kin]." But the policy does not preclude the ground commanders from announcing that an incident has occurred that resulted in the deaths of Americans, as long as the individuals are not immediately identified.

Gen. John Nicholson, the commander of U.S. Forces Afghanistan and NATO's Resolute Support Mission, ordered the change to the policy last month, and it has since been applied twice: on June 10 when three U.S. soldiers were killed and one wounded in an attack in the east, and again on Monday, July 3, when one U.S. soldier was killed and two wounded in Helmand Province.

U.S. Forces Afghanistan did not release a statement or inform the public that an American soldier was killed on Monday. Instead, Wednesday morning the Pentagon released a statement saying that PFC Hansen Kirkpatrick was killed in an indirect fire attack in the Nawah District on July 3. A senior defense official said that the 19-year-old soldier from the 1st Armored Division in Fort Bliss, Texas, was clearing a compound with his partnered Afghan forces when they came under fire. Being hit by both gunfire and mortar rounds, they took up a defensive position to fight back, when a mortar came in and hit Kirkpatrick and two of his fellow American service members.

On June 10, despite the Afghan government saying that Americans had been killed and injured in Nangarhar Province, the U.S. military in Kabul refused to acknowledge the deaths, instead releasing a statement saying, "We are aware of an incident in Eastern Afghanistan. We will release more information when appropriate." Two days later, on June 12, the military acknowledged the three deaths and one injury.

Captain William Salvin, the director of public affairs for Resolute Support, said that Gen. Nicholson decided to change the policy to protect the families of the fallen and of those who continue to serve in the warzone. Nicholson wants to make sure the families have been notified and have their support systems in place before the U.S. military in Kabul informs the public that an incident has occurred, Salvin said, adding "it's most important to take care of the families."

Salvin said that the small footprint of the U.S. military in Afghanistan also factored into Nicholson's decision. With such a small force, families know where their loved ones are operating, and even the vague initial information about incidents in press releases could have been enough to identify a unit or small team.

But while there are fewer U.S. service members in Iraq and Syria than in Afghanistan, the ground commander in Baghdad continues to send out a notification when an incident results in a U.S. death.

And one senior defense official warned that Nicholson's new policy will mean less transparency and more ambiguity about the war in Afghanistan at a time when many Americans don't know what is happening there. "It's a step in the wrong direction," the official said.

The official explained that putting out information about the operational event has nothing to do with identifying the individual casualties. In fact, reporting the incident as it occurs goes back to Vietnam, the official said, citing news reports about helicopter crashes and intense firefights before next of kin were notified. Military historian William Hammond, author of the book "Reporting Vietnam" and an adjunct professor at the University of Maryland, confirmed to NBC News that the practice of reporting incidents as they occur dates back to the Vietnam War.

The Pentagon also used to identify a casualty immediately after the individual's next of kin was notified, the official said, until the 24-hour-notification requirement was introduced in 2009.

Another senior defense official expressed concern about the new policy because it may mean that Afghans become the initial source of information about American casualties. "It's just not appropriate and it's not the way we have been doing things for more than a decade," the official said.

Ultimately, Gen. Nicholson has final say over what information is released and when, both Pentagon and U.S. military officials said. As long as he is commander, the first acknowledgment of the death of an American in Afghanistan will include a note than next of kin have been notified.