The US Navy is preparing to remove 21 Saudi Arabian military students from a training program.
It follows an investigation into a deadly shooting by a Saudi aviation student at a Florida navy base last month.
Those being expelled have not been accused of helping the attacker, although "derogatory material" was found in possession of the 21 members being removed.
US Attorney General William Barr said that 17 of the 21 had "social media containing some jihadi or anti-American content", while 15 "had some kind of contact with child pornography".
Mr Barr said there was "no evidence of any affiliation or involvement with any terrorist activity or group" among the cadets.
In December, 21-year-old Saudi Air Force officer Mohammed Alshamrani killed three US sailors and injured eight other Americans at Naval Air Station in Pensacola.
The gunman, who was a second lieutenant in the Saudi Air Force, also died in the incident.
The Attorney General has now called the attack "an act of terrorism".
Those removed from the training program are to return to Saudi Arabia, but anyone the US decides to charge in relation to the case will return for trial.
Flight training is suspended for approximately 175 Saudi students across three bases during the probe.
Speaking to journalists, William Barr said: "The evidence shows that the shooter was motivated by jihadist ideology."
The Attorney General dismissed early reports that the shooter was joined by other Saudi cadets who were filming the attack.
Two US marines were praised for bravery, and are said to followed the sound of gunfire into the building in an effort to find the shooter.
Though unable to confront the attacker, the pair gave medical aid to those wounded.
One airman was said to have been shot five times, yet managed to "jump on top of a fellow sailor to keep her from being shot" and help others to escape.
Experts have restored two iPhone mobile devices used by the gunman, one of which he had attempted to destroy during the firefight.
However, Attorney General Barr says that the devices are impossible to access without the designated passwords - accusing Apple of providing no “substantive assistance” by refusing to unlock the phone.
Apple is reportedly reluctant to unlock the phones due to concerns this could undermine its encryption software and put public data at risk.
"It is very important to know with whom and about what the shooter was communicating before he died," Mr Barr said.
NAS Pensacola employs more than 16,000 military personnel and 7,400 civilians, according to its website.
Cover image: NAS Pensacola air base (Picture: NAS Pensacola/Facebook).