3. To ensure that this coordinated approach stands the test of time, the mandate of the NIS Cooperation Group Work Stream should be extended, as well as the cooperation with other relevant bodies and entities, in order, in particular, to:  Review periodically - with the support of the Commission and ENISA - the national and EU risk assessments on the security of 5G and post-5G networks, further elaborating and aligning the assessment methodology followed and adapting to the evolving 5G technology.  Perform a detailed and regular monitoring and evaluation of the implementation of the toolbox based on a structured reporting by Member States;  Coordinate and support the implementation of supporting actions, which require cooperation at EU level, in particular regarding the elaboration of guidance and exchange of best practices on the various measures.  Support further possible coordination at EU-level where appropriate, in particular to bring further convergence as regards technical and organisational security requirements for network operators. 19