IAMGOLD Announces Closing of Northern Superior Acquisition

Press Release

Toronto, Ontario–(- December 19, 2025) – IAMGOLD Corporation (NYSE: IAG) (TSX: IMG) (“IAMGOLD” or the “Company”) is pleased to announce that the Company has completed the previously announced arrangement (the “Transaction”) with Northern Superior Resources Inc. (TSXV: SUP) (OTCQB: NSUPF) (GR: D9M1) (“Northern Superior”), pursuant to which IAMGOLD acquired all of the issued and outstanding common shares of Northern Superior (the “NSUP Shares”) by way of a plan of arrangement under Division 5 of Part 9 of the Business Corporations Act (British Columbia).

“With the completion of the acquisition of Northern Superior and its assets, IAMGOLD’s Nelligan Mining Complex in the Chibougamau-Chapais region of Quebec is now among the largest pre-production gold projects in Canada,” said Renaud Adams, President and Chief Executive Officer of IAMGOLD. “We look forward to accelerating our exploration program in the region with a goal of further expansion and extension of the mineralization at Nelligan, Philibert and Monster Lake, as we look to continue to grow the mineralization and advance a project that complements both the scale and timing of our Côté Gold Mine and its forthcoming expansion.”

As a result of the completion of the Transaction and the acquisition by IAMGOLD of all of the NSUP Shares, Northern Superior became a wholly-owned subsidiary of IAMGOLD. Former Northern Superior shareholders are now entitled to receive, in exchange for each NSUP Share held immediately prior to the effective time of the Transaction, a combination of (i) 0.0991 of an IAMGOLD common share and (ii) C$0.19 in cash. The Transaction also included a concurrent distribution to Northern Superior’s shareholders of all the common shares in the capital of ONGold Resources Ltd. previously held by Northern Superior. Full details of the Transaction are included in Northern Superior’s management information circular dated November 10, 2025, which can be found under Northern Superior’s profile on SEDAR+ at www.sedarplus.ca. The NSUP Shares will be delisted from the TSX Venture Exchange and an application will be made for Northern Superior to cease to be a reporting issuer in Ontario, British Columbia, Alberta and Quebec.

About IAMGOLD

IAMGOLD is an intermediate gold producer and developer based in Canada with operating mines in North America and West Africa, including Côté Gold (Canada), Westwood (Canada) and Essakane (Burkina Faso). The Côté Gold Mine achieved full nameplate in June 2025 and has the potential to be among the largest gold mines in Canada. IAMGOLD operates Côté Gold in partnership with Sumitomo Metal Mining Co. Ltd. In addition, the Company has an established portfolio of early stage and advanced exploration projects within high potential mining districts, including the Nelligan Mining Complex located in Quebec, Canada. IAMGOLD employs approximately 3,700 people and is committed to maintaining its culture of accountable mining through high standards of Environmental, Social and Governance practices. IAMGOLD is listed on the New York Stock Exchange (NYSE: IAG) and the Toronto Stock Exchange (TSX: IMG).

IAMGOLD Contact Information

Graeme Jennings, Vice President, Investor Relations
Tel: 416 360 4743 | Mobile: 416 388 6883
Toll-free: 1 888 464 9999
info@iamgold.com

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