U.S. Secretary of State Marco Rubio said Friday that the U.S. Agency for International Development is now in “close-out mode,” confirming that the 63-year-old foreign-assistance body has begun a formal wind-down. Rubio added that Office of Management and Budget Director Russ Vought will oversee the shutdown, after several core programs were transferred earlier this year to the State Department. The administration has argued that winding down USAID will save “tens of billions of dollars,” though it has not released a detailed timetable or cost-benefit analysis. Rubio, who served briefly as acting USAID administrator, first signaled the move in March following President Donald Trump’s directive to consolidate foreign-assistance functions. Public-health experts and development groups warned that eliminating the agency could reverse progress against infectious diseases. A peer-reviewed study cited by critics estimates that the loss of U.S. aid may lead to more than 14 million additional deaths by 2030 from HIV/AIDS, malaria and respiratory infections, particularly in low-income countries. Congressional Democrats said they would seek hearings on the legality of dismantling an agency created by statute in 1961, while some Republicans welcomed the decision as part of broader efforts to streamline government. Until legislation is passed or litigation resolves the matter, USAID will continue to fulfill existing grant commitments during the transition, according to a State Department official.