Nuclear Weapons Abolition and Economic and Energy Conversion Act of 2021 This bill directs the U.S. government to sign and ratify the United Nations Treaty on the Prohibition of Nuclear Weapons or a similar international agreement that calls for the elimination of all nuclear weapons in every country. The government shall (1) redirect resources currently used in nuclear weapons programs toward building an ecologically beneficial peace economy and addressing human and infrastructure needs, and (2) actively promote policies to induce all other countries to take similar actions.