MELBOURNE (Reuters) -Glencore has called its Mount Isa copper smelter unviable and is waiting to hear back on its requests for assistance from state and federal governments to keep the facility open amid tough global conditions, it said on Friday.

The UK-listed miner has been sounding the alarm in local media about its Mount Isa smelting business in Queensland state as its related mining operations are set to close next month.

It will then have to procure copper concentrate to process when excess global smelting capacity has pushed global processing fees to historic lows.

"A combination of unprecedented smelting market conditions, high costs like energy, gas and labour, and a shortage of copper concentrates is currently making the Mount Isa copper smelter unviable," Glencore said in a statement.

Glencore said it has approached both federal and Queensland state governments for support to keep the copper smelter and refinery operating.

Several lawmakers visited the plant on Friday including Australia's industry and science minister, Tim Ayres, and Queensland resources minister, Dale Last.

The state and federal governments have engaged extensively with Glencore to explore options for a viable path forward for the smelter, which is a critical asset for regional and state economies, the ministers said in a joint statement.

"Any closure of the Mount Isa copper smelter would have a detrimental impact on Australia's sovereign capability and other facilities downstream that rely on the smelter," Ayres said in the statement, without giving any details on what options there might be to provide Glencore with any funding.

Glencore said that it had put forward ideas for a "regional solution that would bridge the current economic gap and enable the smelter and refinery to continue operating."

"We want to continue operating the smelter and refinery and look forward to hearing feedback from both federal and Queensland governments on a possible way forward," said Troy Wilson, chief operating officer for Glencore's Australian metals business, in a statement.

(Reporting by Melanie Burton; Editing by Tom Hogue)