and Development Plan that takes into account the evolving threat landscape, annual metrics, and other relevant information to identify priorities and guide research and development requirements and investments. The Secretary shall reissue the plan every 4 years after its initial issuance, and make interim updates as needed. (g) Consistency in PPD–1 Policy coordination, dispute resolution, and periodic in-progress reviews for the implementation of this Act shall be carried out consistent with Presidential Policy Directive 1, including the use of interagency policy committees coordinated by the national security staff. (h) Relationship to other authorities Nothing in this Act alters, supersedes, or impedes the authorities of Federal departments and agencies, including independent regulatory agencies, to carry out their functions and duties consistent with applicable legal authorities and other Presidential guidance and directives, including the designation of critical infrastructure under such authorities. 9. Designation of critical infrastructure sectors and sector-specific agencies (a) Designation (1) In general For purposes of this Act, the Secretary of Homeland Security shall determine which critical infrastructure sectors and sector specific agencies for such sectors should be engaged in efforts to detect, deter, mitigate, and lead recovery efforts related to terrorist incidents. (2) Cultivation of relationships The Secretary shall evaluate the appropriate relationships among Federal agencies, SSAs, SLTTs, and critical infrastructure owners and operators to establish the most effective defense against terrorist attacks. (b) Function The Secretary shall provide institutional knowledge and specialized expertise to lead, facilitate, or support security and resilience programs and associated terrorism prevention activities with respect to sectors designated under subsection (a)(1). (c) Changes The Secretary of Homeland Security shall periodically evaluate the need for and make changes to plans and evaluations