A 21-year-old airman appeared in a US federal court on Friday to face charges of unauthorised removal and retention of classified and national defence information. The judge ordered Jack Teixeira, a Massachusetts Air National Guardsman, to remain in custody until a detention hearing next week. Mr <a href="https://www.thenationalnews.com/world/us-news/2023/04/14/jack-teixeira-pentagon-leak-arrest/" target="_blank">Teixeira was arrested</a> by heavily armed tactical agents on Thursday, under the Espionage Act, following a weeklong criminal investigation into the disclosure of the government records. President Joe Biden commended "the rapid action taken by law enforcement to investigate and respond to the recent dissemination of classified US government documents". The breach exposed to the world unvarnished secret assessments on the war in Ukraine, the capabilities and <a href="https://www.thenationalnews.com/world/2023/04/10/leaked-us-documents-pentagon-mossad-israel-fake/" target="_blank">geopolitical interests of other nations</a> and other national security issues. The leak of dozens of pages of documents has been described as one of the most damaging and embarrassing intelligence disclosures in a decade. The documents were shared among a small group on the Discord text and video chat app before being picked up and circulated more broadly on the Telegram messaging service, where international news organisations first became aware of them. Experts and former officials said it was a serious exposure that highlighted not only up-to-the-minute assessments of Russia’s war in Ukraine, but also how the US collects intelligence around the world. "While we are still determining the validity of those documents, I have directed our military and intelligence community to take steps to further secure and limit distribution of sensitive information, and our national security team is closely co-ordinating with our partners and allies," Mr Biden said. Mr Teixeira wore beige jail scrubs and showed no emotion as the judge read out the charges. His parents were sitting in the front row. They exchanged a brief greeting as he was handcuffed and led away. According to an FBI affidavit released on Friday, Mr Teixeira unlawfully retained and disseminated material <a href="https://www.thenationalnews.com/world/us-news/2023/01/13/classified-documents-biden-trump/" target="_blank">classified at the TS//SCI level</a>, which is the highest classification level. He allegedly began posting text of classified information in a chat room on the Discord social media website in December, which was then followed by photos of classified information including “a document that described the status of the Russia-Ukraine conflict, including troop movements, on a particular date,” according to the affidavit. Mr Teixeira told a chat room user “that he had become concerned that he may be discovered making the transcriptions of text in the workplace, so he began taking the documents to his residence and photographing them,” according to the affidavit. <i>Agencies contributed to this report</i>