; (2) limit the use of branding and marking waivers, as appropriate, for humanitarian assistance provided by the United States to such countries; and (3) only use branding and marking waivers on a case-by-case basis for non-humanitarian programs administered by the Department of State, the United States Agency for International Development, or another Federal department or agency administering programs in such countries. (d) Efforts to limit benefits from illicit extraction and trade in natural resources The Secretary of State, in coordination with the heads of other relevant Federal departments and agencies, shall engage in diplomatic efforts to limit the ability of the Wagner Group, any successor to the Wagner Group that engages in similar conduct, and other Russian mercenary proxy groups to engage in, or materially benefit from, the smuggling and illicit extraction, refining, and trade of gold and other natural resources, including by encouraging— (1) the harmonization of tax regimes; (2) the adoption of due diligence and international standards for conflict-free and responsible sourcing of natural resources