BHP said it would take a US$1.8 billion non-cash deferment charge because of the new "international tax provisions" that have also seen Royal Dutch Shell take a hit of $2 billion.

Changes include restrictions on how past losses can be used to offset the taxes paid on future profits.

The miner said the $1.8 billion would come in two parts: an $898 million non-cash re-measurement of deferred taxes and an $834 million non-cash impairment of foreign tax credits "due to reduced forecast utilisation".

BHP had already flagged an impairment in its upcoming finance report for the six months to December 31.

These will be largely from conveyer issues at Escondida, in the range of $250 million to $350 million.

BHP said the US tax changes overall would be positive because of the corporate tax rate being cut from 35% to 21%.

BHP shares were up less than 1% in London on early trading.