In December 2016, the UN General Assembly adopted resolution 71/125, designating April 26 as International Chernobyl Disaster Remembrance Day, marking the anniversary of the explosion of Reactor No. 4 at the Chernobyl nuclear power plant in Ukraine in 1986 — one of the most severe nuclear disasters in history, which caused widespread radioactive contamination affecting millions of people in Ukraine, Belarus, Russia, and beyond. In its resolution, the General Assembly acknowledged that the health, environmental, social, and economic consequences of the disaster persist even decades later, and that affected communities continue to need ongoing support. The day promotes international solidarity with these communities and underscores the importance of strict nuclear safety standards and continued scientific research into the long-term health effects of radiation exposure. The United Nations and its relevant agencies, together with Ukraine, Belarus, and Russia, mark the day with memorial ceremonies and nuclear safety awareness events, alongside support initiatives for survivors and communities still dealing with the disaster's lasting impact.