"I have to choose one of the two before my 21st [birthday]," he revealed.
In December, an official of the Morocco Football Association claimed Aissati has finally opted to feature for the country of his parents.
According to officials of the Moroccan FA, Aissati, who has both Dutch and Moroccan nationality, has now pledged his international future to the north African country.
A statement by the Moroccan FA said: "Ismail Aissati has decided to play in the colours of Morocco from now on. He and his family announced this to a board member of the Moroccan FA."
The promising midfielder starred for the Dutch Under-21 side that won the European Championship in 2006.
In 2007, he was rumoured to have opted to play for the Atlas Lions of Morocco.
The 20-year-old playmaker joined Ajax from PSV Eindhoven in the summer, but he has been battling a knee injury he suffered in August.
Samm Audu, Goal.com