Tiwai Point aluminium smelter's owner and operator has begun exploring "potential pathways" with electricity generators for a future beyond the plant's previously-signalled closing in 2024.

New Zealand Aluminium Smelters (NZAS) chief executive and general manager Chris Blenkiron said the company understood the importance of providing certainty to its staff and the people of Southland.

"There is lots of work to do, but we believe there is a positive pathway to securing a long-term presence for the smelter," he said in a statement.

"Irrespective of any agreement, we will remediate the site.

"Work is already under way to remove waste, improve our environmental performance, and continue building enduring relationships with our community."

NZAS is majority-owned by the minerals giant, Rio Tinto.

After years in the doldrums, aluminium prices climbed to new highs but were now well off their peak.

The metal last traded at around US$2450 a tonne, down roughly 40 per cent from its March high, but well ahead of an early 2020 level of US$1452 a tonne.

About 85 per cent of the power Tiwai Point consumed was renewably generated, with most of that supply coming from Meridian Energy's Manapouri hydro station.

Blenkiron has in the past said that Tiwai, as a producer of some of the highest purity, lowest carbon aluminium in the world, was well-placed to supply economies focused on decarbonisation.

The future of Tiwai Point was put in doubt two years ago after Rio Tinto announced plans to shut the smelter down in 2021, citing high power costs.

In 2021 it announced it had secured a cut-price power deal from Meridian and Contact Energy to stay open for another four years.

Meridian Energy, Tiwai's main supplier, noted the statement from NZAS.

"Meridian will engage with NZAS as part of its process and expects this will include contract negotiations," the company said in a statement to the NZX.

The current contract to supply Tiwai runs out in December 2024.

NZAS is a joint venture between Rio Tinto, which has a 79.36 per cent share, and Sumitomo Chemical Company (20.64 per cent).