Sherritt International Corp. is shutting down operations at its refinery in Fort Saskatchewan, Alta., after running out of the feed inventory it receives from its Moa mine in Cuba.

The company says the shutdown will continue until mining and processing activities at Moa resume and the refinery feed pipeline is rebuilt.

Operations at Sherritt’s Moa joint venture in Cuba were paused earlier this year as the country faced fuel shortages since the U.S. cut off access to oil from Venezuela in January.

The refinery shutdown comes as the company says it’s in talks with its lenders, but that it would be unable to repay all or a material portion of its debt if it becomes due earlier than its stated maturity as a result of an acceleration by one or more of its creditors. It says its ability to refinance or extend its debt under the current circumstances remains uncertain.

Sherritt has signed a non-binding agreement with Gillon Capital LLC, a family office of a former Trump administration adviser, that would allow Gillon to buy a majority stake in the company.

The Canadian miner has said that a preliminary private placement deal would see Gillon hold a warrant that would allow it to buy enough shares to give it a 55 per cent stake in the company.