Encounter Resources (ASX:ENR) said that the updated mineral resource estimate for its Aileron niobium-rare earth elements-copper project in Western Australia is targeted for the first half of 2026, according to a Friday Australian bourse filing.

It is also conducting metallurgical testwork to produce ferroniobium and niobium oxide at the project.

It plans to begin field operations at the Yeneena copper project, also in Western Australia, to support diamond and reverse circulation drilling at the Tyrell, Parbo, and Haddon prospects from April. It is preparing for diamond drilling to begin in the second quarter, co-funded by the Western Australian state government's Exploration Incentive Scheme.

Its shares fell 5% in recent trading on Friday.