The Belgian National Scientific Secretariat on Invasive Alien Species (NSSIAS) is a scientific body in charge of ensuring the expertise necessary for the coordinated implementation of the EU IAS regulation (N° 1143/2014) in Belgium. The NSSIAS is based at the Royal Belgian Institute of Natural Sciences.
In Belgium, competences pertaining to the execution of the EU IAS Regulation are divided between the three Regional authorities and the Federal State. Since invasive alien species do not adhere to administrative borders and since most of the provisions laid down in the EU Regulation require some level of coordination to ensure coherence and legal security, the competent authorities signed the first Belgian cooperation agreement on nature conservation in 2019. This cooperation agreement calls into life a National Committee on IAS, a National Scientific Council on IAS and the National Scientific Secretariat on IAS.

When more than one authority is implicated in the implementation of the EU IAS Regulation, this matter is taken up by the National Committee. The NSSIAS then supports the National Committee by providing the necessary scientific input. Topics are usually related to the three pillars of the EU IAS Regulation -prevention, early warning and management – and include: providing identification tools and trainings to support the official controls; facilitating dataflows of IAS observations in the framework of early warning systems; supporting the competent authorities in drafting operational action plans on the pathways of introduction and spread by prioritizing pathways of introduction and spread of IAS; developing and leading research projects to inform and support policies and actions; preparing scientific advice on the proposal for update of the list of species of Union Concern; drafting management strategies for listed species and coordinating the reporting to the European Commission.
The NSSIAS works in cooperation with the National Scientific Council, scientific institutions such as the BBPF (Belgian Platform for Biodiversity) and other experts to execute its tasks.