REUTERS/Jonathan Ernst
U.S. President-elect Donald Trump delivered brief remarks to reporters at the Mar-a-lago Club in Palm Beach, Florida, U.S. December 28, 2016.
"There should be no further releases from Gitmo," Trump said in the tweet, using an alternate name for the US detention camp in Cuba. "These are extremely dangerous people and should not be allowed back onto the battlefield."
President Barack Obama vowed to close the detention camp at the beginning of his presidency.
Detainees at Guantanamo Bay are held indefinitely. The military prison opened after the September 11th terrorist attacks on the US to hold suspects captured in the fight against Al Qaeda.
There are 60 detainees left at Guantanamo and about a third have been cleared for release, according to the Associated Press.