(a) Authorization To Reimburse.—The Secretary concerned may reimburse a member of the armed forces under the jurisdiction of the Secretary for travel and related expenses (to the extent not otherwise reimbursable under law) incurred by the member as a result of the cancellation of previously approved leave when—
(b) Regulations.—
The Secretary of Defense and, in the case of the Coast Guard when it is not operating as a service in the Navy, the Secretary of Homeland Security shall prescribe regulations to establish the criteria for the applicability of subsection (a).