"I think streaming the execution for all to see might have been a strong deterrent for the World to witness how America deals with Terrorists and SCUM like Hasan but, many very good and well meaning people would rather not watch him die, through streaming, or through any other visual device," Trump wrote.
"He will die, as scheduled, by firing squad, but this event will not be streamed. That said, the execution may be viewed in person by the immediate families of the victims, if they so choose. They deserve to witness JUSTICE!"
Some of Trump's fellow Republicans, including Vice President JD Vance, as well as religious leaders and international observers had expressed doubts about the Pentagon's plan to livestream the December 3 execution of Nidal Hasan.
Recent US polls have also showed a majority of respondents opposed livestreaming it.
Hasan, a US army psychiatrist who held the rank of major, walked into a medical building on November 5, 2009, where soldiers were waiting in long lines to receive immunisations and medical clearance for deployment.
He shouted "Allahu akbar" - Arabic for "God is great!" - and opened fire with a laser-sighted handgun.
He also shot at the backs of soldiers fleeing towards the parking lot.
Hasan was found guilty in a military trial of fatally shooting 13 people at Fort Hood in Texas.
When asked how the public execution comported with his Christian faith earlier this month, Vance said "I don't know that that's actually going to happen."
"So whatever the controversy is about the method of the execution, I hope that people don't forget that this is a guy who brutally murdered a lot of innocent people," Vance said.
But he continued: "Now, that said, I mean, look, if it's ultimately livestreamed, I'm not going to be watching it."
Hasan is scheduled to be executed on December 3 at the site of the attack.
with AP and DPA
12°C