Prayuth said the appointment of officers to more than half of the assembly's 200 seats was necessary because "the situation was not normal."
"When political parties choose representatives, they choose politicians, right?" Prayuth told an event to promote a new National Reform Council.
The National Legislative Assembly was sworn in Thursday. Its duties will be to appoint a cabinet, enact new legislation and work with the reform council to carry out reforms as directed by the junta.
Prayuth said the council would be established by October 2nd.