Stormont support and more than £80m in funding is needed for a major expansion of special school places in Belfast, according to the Education Authority.
It said special school pupil numbers in Belfast have risen by 40% in a decade.
The Education Authority plans to open a new special school in the city by 2024, and increase the number of pupils at Harberton Special School to 500.
But it added that the plans were not achievable "without cross-departmental support and resources" from Stormont.
There are currently 10 special schools in the Belfast City Council area and 39 across Northern Ireland as a whole - with more than 7,100 pupils, many with complex special educational needs (SEN).
Demand for places in special schools has risen substantially in recent years.
