The Justice Department also said that 21-year-old Jack Teixeira might still have access to classified documents and that "hostile" nations could aid his escape if he is released from prison.

They argued during a detention hearing in Worcester, Massachusetts that Teixeira poses "an ongoing risk" to America's national security and that he should remain in jail until his trial.

Teixeira's defense team said their client no longer had access to classified documents and claimed the government was exaggerating his threat to national security.

The Massachusetts judge hearing the case said he would rule on Teixeira's request to be released pending trial at a later date.

The IT specialist with the US Air National Guard is accused of orchestrating the most damaging leak of US classified documents in a decade.

The documents posted online unveiled US concern over Ukraine's military capacity against invading Russian forces, and showed Washington had apparently spied on allies Israel and South Korea.

Teixeira was arrested earlier this month following a week-long probe and charged with two counts that carry maximum prison sentences of 10 years and five years.

He wrote on social media in November that he wanted to "kill a ton of people" because it would be "culling the weak minded," the prosecution wrote in a court document filed late Wednesday.

Prosecutors also claimed that the airman sought advice from another user about what type of rifle would be easy to operate from the back of an SUV, and that he searched mass shootings online.

They added that Teixeira owned "a virtual arsenal of weapons, including bolt-action rifles, rifles, AR and AK-style weapons, and a bazooka," with some of the firearms "just feet from his bed."

The document said that Teixeira was suspended from school in March 2018 after a classmate "overheard him make remarks about weapons, including Molotov cocktails, guns at the school, and racial threats."

Teixeira poses "a serious flight risk," the prosecutors argued.

"He accessed and may still have access to a trove of classified information that would be of tremendous value to hostile nation states that could offer him safe harbor and attempt to facilitate his escape from the United States," the filing said.

Teixeira, who has not yet entered a plea, is accused of the "unauthorized retention and transmission of national defense information" and the "unauthorized removal and retention of classified documents or material."

His lawyers argued that Teixeira should be released into his father's custody pending trial.

The prosecution "engages in hyperbolic judgements and provides little more than speculation that a foreign adversary will seduce Mr Teixeira and orchestrate his clandestine escape from the United States," the defense said in submissions.