A Canadian miner that is one of Cuba’s biggest foreign investors warned investors that its ability to carry on as a going concern is in doubt after Donald Trump expanded US sanctions on the Caribbean nation.

Sherritt International Corporation said its ability to meet or refinance its debt “remains uncertain.” The terms of its C$79.5-million ($56-million) credit facility allow lenders to declare a default and demand early repayment because of the US President’s executive order, which targeted foreign companies operating in the communist-run country.

Sherritt said in interim results published Thursday that it wouldn’t have enough cash to repay if lenders exercised that right, and it would need to seek alternative financing. And in that case, bondholders may also have the right to ask to be repaid early.

The Toronto-based company halted production at its nickel and cobalt mine in eastern Cuba in February because of a dire energy crisis on the island. In May, it delayed the release of its first quarter results after Trump issued his order, and the company’s CFO and auditor resigned.

After initially moving to dissolve its joint venture with a Cuban State-owned company and exit the island, Sherritt announced it had struck a preliminary financing deal to sell a controlling stake to Gillon Capital LLC, the Texas-based family office of a former Trump adviser.

While the Canadian miner entered into exclusive talks with Gillon earlier this month, its operations in Cuba remain shuttered. This week, Sherritt announced it was idling its Alberta refinery — one of only three facilities that processes nickel in North America, and the only one that refines cobalt — because its supply of raw material from Cuba had dried up.

The company “has and will undertake numerous initiatives available to it to continue to strengthen its financial position and enhance liquidity,” Sherritt said. It cited cost and workforce reductions and capital spending cuts, as well as payment deferrals and a recent equity injection.

But the production halt and Trump’s expanded sanctions “result in material uncertainty which may cast significant doubt about the Corporation’s ability to continue as a going concern,” Sherritt said.