Nidal Hasan called no witnesses and offered no testimony in his defence, raising concerns among court-appointed lawyers that he was seeking execution. (AFP pic)

WASHINGTON: The execution by firing squad of convicted military base shooter Nidal Hasan will be livestreamed, a Pentagon official said Thursday, after defence secretary Pete Hegseth said it would be carried out in "public".

Hasan, a US Army psychiatrist, shot dead 13 people at Fort Hood in 2009. His execution will be the first by the US military since 1961, and the first it has carried out by firing squad since World War II.

"It will be livestreamed. Details will follow," the Pentagon official told AFP on condition of anonymity.

Hegseth had said in a video posted on X by official Pentagon accounts earlier Thursday that Hasan is "going to get a firing squad of soldiers, as it should be, and we'll make sure that people are able to watch it, that it's public."