This January 6, 2015 aerial photo shows the Pentagon building in Washington, DC. FREDERIC WALLOIS / AFP

The Pentagon has unveiled new restrictions on media outlets covering the US military, requiring them to pledge not to disclose anything not formally authorized for publication and limiting their movements within the Department of War.

The new guidelines, laid out in a lengthy memo distributed to reporters on Friday, September 20, require them to sign an affidavit promising to comply – or risk losing their media credentials. The move is the latest by the Trump administration to control media coverage of his policies, and after the US president suggested that negative stories could be "illegal."

The Pentagon "remains committed to transparency to promote accountability and public trust," the memo says. Yet it adds: "Information must be approved for public release by an appropriate authorizing official before it is released, even if it is unclassified" – effectively barring material sourced to unnamed officials. This new restriction would apply to both classified and "controlled unclassified information."

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