41 C.F.R. § 101-26.311
(a) At the request of the ordering agency, GSA may authorize diversion or return for credit of any shipment consigned to an overseas destination which, while en route, cannot be continued onward for any reason and for which the consignee or requisitioning agency cannot provide diversion instructions:
Provided, The frustration occurs at a water or air terminal and title to the material has not passed from the Government. Frustrated shipments located outside the United States are the responsibility of the consignee or ordering agency. However, GSA will assist the agency whenever possible in disposing of the material when it cannot be utilized by the overseas control area of the agency, e.g., oversea command or AID area.
(c) GSA may direct disposition of such material through any of the means listed below. Disposition instructions will include a determination by GSA as to the responsibility for payment of transportation costs.
[30 FR 11138, Aug. 28, 1965, as amended at 35 FR 12721, Aug. 11, 1970; 42 FR 58748, Nov. 11, 1977]