Ur-能源美股招股说明书(2025-10-20版)

19,137,000 Common Shares Issuable upon Exercise of 38,274,000Warrants to Purchase Common Shares We are offering to the holders of warrants to purchase up to 19,137,000 shares of our common stock, no par value (the“common shares”), subject to certain adjustments set forth in the warrants (the “warrants”), the common shares issuable upon exerciseof the warrants. Our common shares are listed on the NYSE American (the “NYSE American”) under the symbol “URG” and on the TorontoStock Exchange (the “TSX”) under the symbol “URE”. On October 17, 2025, the last reported sale price of our common shares on theNYSE American and the TSX was $1.61 per share and Cdn$2.24 per share, respectively. We have not engaged any financial advisor in connection with this offering. Investing in our common shares involves risks. See “Risk Factors” beginning on page S-8 of this prospectussupplement and page 2 of the accompanying prospectus to read about risks that you should consider before buying ourcommon shares. You should carefully read this prospectus supplement and the accompanying prospectus, together with thedocuments we incorporate by reference, before you invest in our common shares. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Anyrepresentation to the contrary is a criminal offense. Prospectus Supplement dated October 20, 2025 Table of Contents PROSPECTUS SUPPLEMENT ABOUT THIS PROSPECTUS SUPPLEMENTS-1CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSS-2CAUTIONARY NOTE TO INVESTORS CONCERNING DISCLOSURE OF MINERAL RESOURCESS-5CURRENCY AND EXCHANGE RATESS-5PROSPECTUS SUPPLEMENT SUMMARYS-6THE OFFERINGS-7RISK FACTORSS-8DILUTIONS-9USE OF PROCEEDSS-10DESCRIPTION OF SECURITIESS-11CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONSS-11CERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONSS-11LEGAL MATTERSS-12EXPERTSS-12WHERE YOU CAN FIND MORE INFORMATIONS-12INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCES-13 PROSPECTUS ABOUT THIS PROSPECTUS1RISK FACTORS2WHERE YOU CAN FIND MORE INFORMATION13INCORPORATION OF CERTAIN INFORMATION BY REFERENCE13CAUTIONARY NOTE TO U.S. INVESTORS CONCERNING DISCLOSURE OF MINERAL RESOURCES14CURRENCY AND EXCHANGE RATES14CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS15OUR BUSINESS17USE OF PROCEEDS18PLAN OF DISTRIBUTION19DESCRIPTION OF SENIOR AND SUBORDINATED DEBT SECURITIES21DESCRIPTION OF COMMON SHARES28DESCRIPTION OF WARRANTS30DESCRIPTION OF UNITS31DESCRIPTION OF RIGHTS32DENOMINATIONS, REGISTRATION AND TRANSFER33CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS34CERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONS36LEGAL MATTERS46EXPERTS46 ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement relates to a prospectus which is part of a registration statement on Form S-3 (File No. 333-272992) that we have filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process.Underthis shelf registration process, we may, from time to time, offer debt securities, common shares, warrants, units and rights. We are responsible for the information contained and incorporated by reference in this prospectus supplement, theaccompanying prospectus and any applicable free writing prospectus we issue. We have not authorized anyone to give you any otherinformation and we do not take any responsibility for any other information that others may give you.We are not making an offer ofthese securities in any jurisdiction where the offer is not permitted. You should assume that the information appearing in each of thisprospectus supplement, the accompanying prospectus, the documents incorporated by reference into this prospectus supplement andthe accompanying prospectus and any related free writing prospectus is accurate as of the respective dates of those documents.Ourbusiness, financial condition, prospectus and results of operations may have changed since those respective dates.You should read thisprospectus supplement, the accompanying prospectus, the documents incorporated by reference into this prospectus supplement andthe accompanying prospectus and any related free writing prospectus when making your investment decision. This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offeringand adds to, updates and changes information contained or incorporated by reference in the accompanying prospectus and thedocuments incorporated by reference into the accompanying prospectus. The second part is the accompanying prospectus, which givesmore general information, some of which may not apply to this offering. To the extent the information contained or incorporated byreference in this prospectus supplement differs or varies from the information contained or incorporated by reference in theaccompanying prospectus or any document incorpor