With regard to any claim arising under this chapter or under the Richard B. Russell National School Lunch Act [
42 U.S.C. 1751 et seq.], the Secretary shall have the authority to determine the amount of, to settle and to adjust any such claim, and to compromise or deny such claim or any part thereof. The Secretary shall also have the authority to waive such claims if the Secretary determines that to do so would serve the purposes of either this chapter or the Richard B. Russell National School Lunch Act. Nothing contained in this subsection shall be construed to diminish the authority of the Attorney General of the United States under
section 516 of title 28 to conduct litigation on behalf of the United States.