The management team of Tara Mines has said the decision to suspend operations is "unavoidable."
Talks between the management and unions for the more than 600 workers at the mines had been ongoing for the last week in a hope to avoid the closure of the mines from next month.
In a statement this morning, the management team said that proposals from the unions did "not sufficiently address the significant and unsustainable losses" that the business is experiencing.
General manager of the mines Gunnar Nystrom added that the group hadn't "taken the decision lightly".
The group explained: "The management has reviewed in detail all the proposals that have been presented, and believe that a number of the measures presented have the potential to deliver benefits to our operation over the medium to long term.
"Unfortunately, the proposals will not sufficiently address, in the short term, the significant and unsustainable losses that the business is currently experiencing.
"These losses have been driven by several factors including a decline in the price of zinc, high energy prices, general cost inflation and operational challenges."
Mr Nystrom said: “We believe this is the best course of action to safeguard the long-term future of the mine. We will continue to work constructively with all stakeholders to ensure the operation can re-open as soon as possible.”