Al-Asmar was detained three years ago on suspicion of having links with the al-Qaida network.
He said there were still five Jordanians, including two brothers, in Guantanamo.
A release order had been issued for 11 other detainees, including a Yemeni and an Algerian, but they had refused to return to their countries, he added.
The US government had released more than 200 detainees
from Guantanamo, some of whom were transferred to detention centres in their home countries.
The camp has been the focus of worldwide controversy following allegations that US forces abused detainees there.