The chief executive of Nyrstar Australia says the metal processor urgently needs to secure a government rescue package to ensure a future for its loss-making smelters in South Australia and Tasmania as the company’s Swiss owner weighs whether to close the plants within weeks.

Matt Howell, who took over as chief executive of Nyrstar Australia in January, has been locked in talks with the federal, South Australian and Tasmanian governments for months on assistance. The three governments are now close to a deal, with an outcome expected as early as this week.