East Star Resources - VMS Drilling Update

16 September 2025

East Star Resources Plc

("East Star" or the "Company")

VMS Drilling Update

Sulphides logged in every hole; assays pending

East Star Resources Plc (LSE:EST), which is exploring for copper and gold in Kazakhstan, is pleased to provide an update on drilling activities, which have been ongoing at the Company's VMS copper targets and the Verkhuba Copper Deposit ("Verkhuba") in East Kazakhstan since mid-June.

The Company has completed its current drill programme with 2,302.8 m of drilling across nine holes over the three target areas:

·    RU_25_DD001 - drilled to 400.3m, located at the northern end of the Rulikha IP anomaly

·    TAL_24_DD001 - drilled to 305.5m at the Talovskoye West IP anomaly

·   VU_25_DD009 - VU_25_DD-015 - drilled a total of 1,597m targeting the central orebody and resource extensions to the shallowest part of the resource model at Verkhuba (see Figure 1)

Drilling has now been completed with five of the holes logged, cut, sampled and sent to the ALS laboratory in Karaganda, Kazakhstan, for assay. The remaining four holes will be sent over in the coming weeks, with assay results expected from the end of Q3 and into Q4 2025.

Although assay results are pending, East Star is pleased to confirm that all holes have recorded sulphides in the target formations. Most notably, mineralisation was observed outside of the current resource envelope at Verkhuba where four drill holes focussed on extending the shallowest part of the deposit to the north.

East Star is planning further exploration work at all three locations, including geophysical surveys and follow-up drilling.

Alex Walker, East Star CEO, commented:

"Drilling has been conducted safely and on budget, with mineralisation observed in all holes. We look forward to receiving the assay results and, for Verkhuba, updating the resource model in Q4 2025.

In addition to drilling in the East region, East Star has also had field teams out in the Karaganda region, visiting more than 20 targets, prospective for copper/gold porphyry and epithermal gold deposits, derived from our participation in the BHP Xplor programme in 2024. Several applications have been lodged as a result of this work, which we expect to update the market on in Q4 2025.

Further work has also been undertaken at the Snowy epithermal gold target, including site visits and sampling by Australian specialists in epithermal gold deposits. We are pleased with the prospectivity of this licence and will provide an update on this work in the near future."

East Star Resources Plc

Alex Walker, Chief Executive Officer

Tel: +44 (0)20 7390 0234 (via Vigo Consulting)

SI Capital (Corporate Broker)

Nick Emerson

Tel: +44 (0)1483 413 500

Vigo Consulting (Investor Relations)

Ben Simons / Peter Jacob

Tel: +44 (0)20 7390 0234

About East Star Resources Plc

East Star Resources is focused on the discovery and development of copper and gold in Kazakhstan. East Star's management are based permanently on the ground, supported by local expertise. The Company is pursuing multiple exploration strategies:

·    Volcanogenic massive sulphide (VMS) exploration, which to date includes a deposit with a maiden JORC MRE of 20.3Mt @ 1.16% copper, 1.54% zinc and 0.27% lead, in an infrastructure-rich region, amenable to a low capex development

·    Copper porphyry and epithermal gold exploration, with multiple opportunities for Tier 1 deposits, initially supported by an initial US$500k grant from BHP Xplor in 2024

Visit our website:

www.eaststarplc.com

Follow us on social media:

LinkedIn: https://www.linkedin.com/company/east-star-resources/

X: https://x.com/EastStar_PLC

Subscribe to our email alert service to be notified whenever East Star releases news:

www.eaststarplc.com/newsalerts

The person who arranged for the release of this announcement was Alex Walker, CEO of the Company.

This announcement contains inside information for the purposes of Article 7 of Regulation 2014/596/EU which is part of domestic UK law pursuant to the Market Abuse (Amendment) (EU Exit) Regulations (SI 2019/310) ("UK MAR"). Upon the publication of this announcement, this inside information (as defined in UK MAR) is now considered to be in the public domain.

Competent Person Statement

Scientific or technical information in this disclosure related to exploration was reviewed by Dr Tremain Woods, a full-time employee of Discovery Ventures Kazakhstan Ltd, a 100% owned subsidiary of East Star Resources PLC. Dr Woods is a member in good standing with the Geological Society of South Africa. He has sufficient experience that is relevant to the commodity, style of mineralisation or type of deposit under consideration and activity which he is undertaking to qualify as a Competent Person under the JORC code (2012 Edition).