Whenever the legislative body determines that it is desirable for the general welfare and benefit of the people, and for the interest of the local agency, it may incur an indebtedness evidenced by negotiable bonds to acquire or improve lands desired to be conveyed to the United States for use by the Defense Department or as customs and immigration offices in consideration of the benefits to be derived by the local agency from the use of the lands by the United States for such purposes. Such bonds may be issued in an amount not exceeding the limitations imposed by law upon the general bonded indebtedness of the local agency.