After an invite to return to negotiations was rejected by the the 2,500-member Escondida union, BHP Billiton announced that it would move forward at the copper mine in Chile and restart operations without the union’s involvement.

The Escondida copper mine, the world's largest copper mine, will first resume work in two areas of the mine that are unrelated to the current talks, Escondida Mine President Marcelo Castillo said at a news conference in the city of Antofagasta.

The company will then begin to do additional maintenance work, before finally re-establishing mining operations and restarting copper production.

“We hope that in some way opportunities for dialogue come about...but with the posture that we saw yesterday (from the union) and that all of you saw yesterday, it’s difficult to be able to hope for a conversation in the short term,” Castillo said.

Reuters reported that under Chilean law the mine was allowed to hire temporary workers 15 days after the strike started on Feb. 9, but had said it would wait for 30 days to show its commitment to dialogue. On the day of the announcement to move forward it was the 34th day of the strike.

In response to BHP’s statement, the union said it was taking a level-headed approach to the latest development.

Copper production has been halted since the 2,500-member union went on strike. On March 13, workers rejected a company invitation to return to the table, saying the invitation did not take into account workers’ pre-conditions for dialogue.

Union demands include that BHP agrees not to trim benefits in the existing contract, that shift patterns should not be made more taxing for workers, and new workers be offered the same benefits as those already employed at the mine.

It was the third failed attempt to restart dialogue during the strike, which has pushed global copper prices higher due to supply concerns.

Escondida produced slightly more than 1 Mt (1.1 million st) of copper in 2016, making it the world’s largest copper mine.

Rio Tinto and Japanese companies such as Mitsubishi Corp hold minority interests in the mine.