It said ongoing exploration efforts had included 1,000 holes comprising 76,000m drilled since December, which had extended the mineralised zone to an area 4km long and 3km wide.
The drilling confirmed the high-grade nature of the Kari Pump target and expanded the mineralisation to 1.3km along strike and across a width of 160-200m, while remaining open to the north and northwest.
The Kari Center discovery extended 1.2km along strike and across a 200m width, while the Kari West high-grade discovery extended 1km along strike and across a 500m width. Both had mineralisation open at depth, with the latter's also open towards Kari Pump.
The wider Kari area hosts a large gold-in-soil geochemical anomaly over a 6km by 2.5km area, with around 25% of the anomaly left to be drilled.
Endeavour is carrying out a further 65,000m drilling campaign to delineate and extend the three discoveries and aims to obtain a maiden resource at Kari Pump by the end of the year through in-fill drilling.
Endeavour executive president exploration and growth Patrick Bouisset said an extensive drilling campaign had been undertaken on the wider Kari target due to its potential size and higher-grade nature, with more than half of the planned 141,000m drilling already completed.
"We are eager to delineate a first maiden resource on the Kari Pump area by year-end," he said.
CEO Sebastien de Montessus said the company was eager to pursue additional upside from exploration after ramping up Houndé and getting the plant performance above nameplate capacity.
"These new discoveries provide confidence in achieving our strategic objective of maintaining a steady production profile at an attractive all-in sustaining cost over at least 10-years," he said.