Mexican President Andres Manuel Lopez Obrador’s government has been criticized by the mining industry for its policy of no new concessions, as well as what have been described as unprecedented regulatory delays.

Earlier this month, Lopez Obrador further stoked industry concerns by proposing a constitutional reform that would restrict future lithium mining, in addition to placing similar limits on other “strategic minerals” needed for the country’s energy transition.

“We are in an unfavorable environment right now,” Fresnillo Chief Executive Octavio Alvidrez said in a mining conference in Acapulco.

Dialogue with the government could lead to policy modifications, Alvidrez added, without going into details.

The chief executive noted that last year the mining sector was initially left out of the government’s designation as an “essential’ industry, and as a consequence was forced to shut down for a couple months.

But after dialogue with authorities, he added, mining was later deemed essential and mines across the country were allowed to open back up.