Officials said the achievement was made in mid-March and is the first of three underground operations to reach the goal.

The other mines in its production expansion, cost reduction and organic growth-driven efforts include the Guanaceví mine in Durango state, and the Bolañitos and El Cubo mines in Guanajuato state.

El Compas is the company's fourth Mexican mine. Its Terronera project in Jalisco is advancing to a development decision, and it is exploring the Parral project in Chihuahua to expand resources.

El Compas has a nominal plant capacity of 250t per day at estimated recovery rates of 83% gold and 50% silver. It processed stockpiled development ore between February 18 and March 17; average production totaled of 232t/d (or 93% of design rate) and recovery rates of 73.5% gold (or 88% of design rate) and 45.5% silver (or 63% of design rate).

"The El Compas mine and plant have operated smoothly at above 80% of design capacity since mid-February," CEO and director Bradford Cooke said. "The start-up issues we experienced have all been resolved; we now have a spare mill trunnion on site, and our focus has moved to optimising the production tonnes, grades and recoveries."

Zacatecas is the third largest historic silver mining district in Mexico. The mine, located just south of Zacatecas City and accessed via a maintained all-weather road, was acquired in 2016 and development commenced 2017. Commissioning start was confirmed last year.