Mr. Peter Akerley reports

ERDENE PROVIDES Q1 2026 BAYAN KHUNDII GOLD MINE UPDATE

Erdene Resource Development Corp. has provided a Bayan Khundii gold mine (BK) production update for Q1 2026, operated by Erdene Mongol LLC (EM), the company's joint venture with Mongolian Mining Corp. (MMC). All dollars are United States unless otherwise noted.

Peter Akerley, Erdene's president and chief executive officer, stated: "During the first quarter of 2026 the Bayan Khundii gold mine achieved commercial production, realizing average throughput of nearly 90 per cent of nameplate capacity. Gold recovery during the quarter averaged over 96 per cent, exceeding projections in the most recent feasibility study. As we transition through ramp-up, we are delivering higher grade ore to the BK process plant."

Mr. Akerley continued, "With a 20-per-cent increase in sales compared to the first quarter of operations, Bayan Khundii has produced 15,961 ounces of gold to date."

Mr. Akerley concluded: "With the proceeds from the financing completed during the quarter, Erdene is positioned to advance our wholly owned high-quality precious and base metal projects in the Khundii and Oyu Tolgoi districts. Exploration, technical studies and permitting are well under way."

Bayan Khundii gold mine -- Q1 2026 update

Bayan Khundii processed 151,000 tonnes of ore, averaging 1,675 tonnes per day, or 94 per cent of the target production throughput during the quarter ended March 31, 2026.

The processed grade averaged 1.9 grams per tonne gold for the quarter ended March 31, 2026, as lower-grade ore was fed during the early part of the period, when mining was reduced to allow for the establishment of a single working level and access to multiple high-grade zones. As operations moved into March, ore feed grades increased significantly, averaging 2.7 g/t gold for the month. Quarterly gold recoveries of over 96 per cent were superior to the forecast average of 93 per cent.

EM sold 8,527 ounces of gold and 3,135 ounces of silver at average prices of $4,872/ounce and $80/oz gold and silver, respectively, generating gross revenues of $42-million ($57-million (Canadian)) during the quarter ended March 31, 2026.

EM's focus in Q2 is on continued optimization of mining and processing operations. Grade control, blasting, mining, stockpile management, crushing improvements and processing throughput increases are aimed at reaching production consistent with historical projections. Those efforts are expected to deliver positive results as the company moves into Q2 aided by improved seasonal conditions for pit operations. In Q3, EM will update resources for the EM deposits and mineral reserves and mine plans for BK and Dark Horse.

Q1 2026 conference call details

Erdene will release its unaudited financial and operating results for the three months ended March 31, 2026, on Wednesday, May 6, 2026, after market close. The company will host a conference call and webcast to discuss the results on Thursday, May 7, 2026, commencing at 9 a.m. Eastern Time. The webcast will be accessible on-line.

The dial-in numbers for the conference call are as follows:

• North America (toll-free): 1-800-717-1738;
• Overseas or local (Toronto): 1-289-514-5100.

Qualified person

Jon Lyons, FAusIMM, chief development officer for Erdene, is the qualified person as that term is defined in National Instrument 43-101 and has reviewed and approved the technical information contained in this news release.

About Erdene Resource Development Corp.

Erdene Resource Development is a Canada-based resource company producing gold at the high-grade, low-cost Bayan Khundii gold mine in underexplored and highly prospective Mongolia. The company has interests in a highly prospective portfolio of precious and base metal projects in close proximity to the Bayan Khundii gold mine in the Khundii minerals district, which provides a robust organic growth pipeline. Erdene Resource Development Corp. is listed on the Toronto (ERD) and the Mongolian stock (ERDN) exchanges and OTCQX Market (ERDCF).

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