United States Climate Leadership in International Mitigation, Adaptation, and Technology Enhancement Act of 2021 This bill sets out priorities for climate action, clean energy, energy diplomacy, reduced deforestation, and related U.S. foreign policy. The Department of State must incorporate climate action and climate diplomacy across all bureaus and U.S. missions abroad. In addition, the bill directs increased U.S. involvement in international climate change agreements and activities, including the Paris Agreement (a climate treaty adopted in 2015), the Kigali Amendment to the Montreal Protocol (amends a treaty on reducing ozone-depleting compounds to include hydrofluorocarbons) and efforts to reduce short-lived climate pollutants, the Carbon Offset and Reduction Scheme for International Aviation, and Mission Innovation and the Clean Energy Ministerial (global initiatives to advance clean energy technologies and policies). In addition, the bill directs (1) increased U.S. engagement in international economic forums (e.g., G-7 and the World Economic Forum) related to climate action, including with a specific focus on China; and (2) efforts by the U.S. International Finance Development Corporation and U.S. representatives at international financial institutions to prioritize renewable energy projects and advance other climate-related policy objectives. The bill also establishes foreign assistance, financing mechanisms, and other programs to support developing countries transition to renewable energy and reduce carbon emissions. Furthermore, the bill outlines climate-related foreign policy and programs for particular regions (the Arctic, sub-Saharan Africa, the Caribbean, Europe, and North America) and countries (China, India, Brazil, and Indonesia). The bill also addresses climate change and its effects on women and girls.