The primary teachers' union is calling on the Government to make a stronger commitment to upskill teachers in Te Reo Rangatira, to help it reach all tamariki.
The call followed an article by philanthropist Gareth Morgan, which said Te Reo should be made compulsory in schools.
NZEI said although that would be ideal, resources were needed to ensure current educators could meet that demand.
The union's matua takawaenga, Laures Park, said many teachers wanted to advance their Te Reo, but were not always supported to do so.
She said unless there was a real government incentive to upskill, teachers would continue to take time out of their lives to take night and weekend classes - a long and drawn out process.
In a statement, Education Minister Hekia Parata said the Government was working hard to increase the number and quality of teachers through recruitment initiatives, such as TeachNZ scholarships.
It is not currently compulsory to offer Te Reo in schools and the Maori curriculum sits within the languages area of the curriculum.