Anglo American will divest from its South African and Colombian thermal coal operations by mid-2023, the miner said on Friday as it sought to demonstrate to investors its commitment to a shift towards clean energy sources.

The global miner said a de-merger and listing on the Johannesburg Stock Exchange was the most likely route for its South African thermal coal assets.

Anglo American, which produces platinum, copper, diamonds, iron ore, and thermal and metallurgical coal, highlighted its green credentials as the mining industry faces increasing scrutiny over its carbon footprint.

"With the bulk of options in copper, PGMs, and now also crop nutrients, we are increasingly positioned to supply those metals and minerals that enable a cleaner, greener, more sustainable world," Chief Executive Mark Cutifani said on Friday in an annual update to investors.

Cutifani said the company planned to exit its Cerrejon thermal coal mine in Colombia within 1 1/2 to 2 years, while the South African thermal coal exit will happen within 2 1/2 years.

Anglo American said production across all minerals will increase by 14% in 2021 and unit costs are expected to fall by 3%.

Capital expenditure would be between $5.7 billion and $6.2 billion next year, reflecting deferred 2020 spending and new investments.

Anglo American expects to deliver output volume growth of 20%-25% over the next three to five years, with the Quellaveco project in Peru producing its first copper in 2022.

The miner sees copper production of between 640,000 and 680,000 tonnes in 2021, and gave a new forecast for 2023 of 890,000 to 1 million tonnes as it seeks to boost production of the metal used in electric vehicles.

The De Beers owner trimmed its diamond production forecasts too, as the diamond unit reduces supply following a slump in rough diamond prices heightened by the pandemic.

Current prices will increase pressure on producers and output will shrink unless they rally, Cutifani said.

Anglo American Platinum said it would return to pre-pandemic production levels from 2021.