From the Summary: "U.S. assistance to Vietnam for the environmental and health damage attributed to a dioxin contained in Agent Orange and other herbicides sprayed over much of the southern portion of the country during the Vietnam War remains a significant bilateral issue. Between fiscal years (FY) 2007 and 2021, Congress appropriated nearly $390 million to address these two issues. This includes $60 million in Department of Defense funds transferred to the Secretary of State, for use by the U.S. Agency for International Development [USAID], for the dioxin clean-up at the Bien Hoa airbase. [...] Congressional interest in Agent Orange/dioxin in Vietnam has largely been focused on two issues. The first issue is determining the appropriate amount and type of assistance to provide to address the environmental damage and the health effects of dioxin contamination in Vietnam. The second issue is oversight of how such assistance has been utilized by the State Department and USAID."
CRS Report for Congress, R44268
Congressional Research Service: https://crsreports.congress.gov/