The U.S. Army Corps of Engineers may assist federal agencies both domestically and overseas.

SECTION 607 OF THE FOREIGN ASSISTANCE ACT OF 1961 (22 USC 2357):  Section 607 authorizes the President of the United States to furnish services and commodities on an advance-of-funds or reimbursable basis to friendly countries, international organizations, the American Red Cross, and voluntary nonprofit-relief agencies registered with and approved by the U.S. Agency for International Development, when the President determines it is in furtherance of the goals of the Act.

SECTION 632a and 632b  OF THE FOREIGN ASSISTANCE ACT OF 1961(22 USC 2392):  Section 632a authorizes the President of the United States to allocate or transfer funds to any U.S. Government agency, including advances by any country or international organization for the procurement of commodities, defense articles, military education/training or services.  Section 632b provides the authority for any U.S. Government official carrying out functions under this Act may utilize said services from any other U.S. Government agency as the President shall direct, or with the consent of the head of such agency.

SECTION 234, WATER RESOURCES DEVELOPMENT ACT OF 1999 (33 U.S.C. 2323a):  Section 234 authorizes the Secretary of the Army to engage in activities in support of other federal agencies or international organizations to address problems of national significance to the United States.  The Secretary may use USACE technical and managerial expertise to address domestic and international problems related to water resources, infrastructure development, and environmental protection.  Section 234 also authorizes some appropriated funding to use in providing support

ARMS EXPORT CONTROL ACT (22 USC 2769 - Foreign military construction sales):  This Act authorizes the president of the United States to sell design and construction services to any eligible foreign country or international organization if such country or international organization agrees to pay in United States dollars not less than the full cost to the United States Government of furnishing such services.