Jack Teixeira -- a 21-year-old Air National Guard IT specialist -- allegedly orchestrated the most damaging leak of US classified documents in a decade, posting a trove of highly sensitive information in an online chat forum.

The documents, which soon spread across the internet, pointed to US concern over Ukraine's military capacity against invading Russian forces and showed Washington had apparently spied on allies Israel and South Korea, among other sensitive details.

Prosecutors argued that Teixeira might still have access to classified documents and that "hostile" nations could aid his escape if he was released from prison, also saying he had a history of making "violent" statements.

Teixeira's defense team said their client no longer had access to such documents and that the government was exaggerating the threat he posed, arguing he should be released into his father's custody pending trial.

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