"Would love to send the NYC terrorist to Guantanamo but statistically that process takes much longer than going through the Federal system", Trump has stated in a tweet.
It was legally questionable whether the Trump administration could have sent 29-year-old Sayfullo Saipov to Guantanamo, in part because the courts have not ruled whether the 2001 Authorization for Use of Military Force - which permits the government to detain enemy combatants for the duration of a military conflict - applies to the Islamic State and its followers.
In the wake of a deadly terrorist attack in NY earlier this week, Trump on Wednesday suggested he'd be open to holding the suspect, a 29-year-old Uzbek national who has lived in the United States since 2010, as an enemy combatant at the Cuba facility nicknamed Gitmo.
Trump tweeted Thursday that there is "also something appropriate" about keeping Saipov "in the home of the disgusting crime he committed".
Speaking to the press Wednesday, the president called the justice system "a laughingstock" and said he would consider sending the suspect to Guantanamo Bay. He killed 8 people, badly injured 12.
"They'll go through court for years".
Separately, the Federal Bureau of Investigation was questioning people who might have information about his actions before the attack, including a second Uzbek man.
Saipov has also been charged with providing material support to Islamic State.
Mr Trump was also very critical of Bergdahl, repeatedly calling him a "dirty, rotten traitor" who deserved to be executed by firing squad or thrown out of a plane without a parachute. "Send him to Gitmo, I would certainly consider that, yes".
On Wednesday, Trump said he felt the USA criminal justice system was "a joke" because it took too long for accused terrorists - "these animals", he called them - to be prosecuted, convicted and sentenced.
On Wednesday, Trump vowed to "get rid" of the green card lottery "as soon as possible", seizing on the NY attack to press his campaign-agenda of restricting immigration.
Investigators work around the wreckage of a Home Depot pickup truck a day after it was used in a terror attack in NY on November 1, 2017.
The military system is different to the country's federal criminal but as legal news website Above The Law pointed out: "when the President of the United States says you should be killed before you've even been tried, it causes real problems for the administration of justice".
Bahij Chancey, 26, center, holds a photo of his friend and, one of the victims Nicholas Cleves, during an interfaith vigil for peace at Foley Square in response to the Manhattan truck attack, Wednesday, Nov. 1, 2017, in NY.
This is because Mr Trump's comments may be used to argue that Saipov won't get a fair trial because the President has already suggested he is guilty and deserves to be put to death.
He has also supported the idea of sending the suspect to Guantanamo Bay terrorist detention centre in Cuba.
"The folks in that unit working with the (New York Police Department) and the (Joint Terrorism Task Force) have a long and unblemished track record of successfully investigating and prosecuting domestic and worldwide terrorists", Kim said.