With respect to any project designated as a high priority under section 2 of this order, the Chairman of the CEQ shall coordinate with the head of the relevant agency to establish, in a manner consistent with law, expedited procedures and deadlines for completion of environmental reviews and approvals for such projects. All agencies shall give highest priority to completing such reviews and approvals by the established deadlines using all necessary and appropriate means. With respect to deadlines established consistent with this section that are not met, the head of the relevant agency shall provide a written explanation to the Chairman explaining the causes for the delay and providing concrete actions taken by the agency to complete such reviews and approvals as expeditiously as possible.