Mr Mackenzie made the comments as BHP delivered a $US6.73 billion ($8.5 billion) full year underlying profit, revealed it would pay $US4.4 billion in dividends for the year - well above its minimum payout commitment - and confirmed it planned to sell its controversial onshore US shale assets.

BHP's underlying profit, which was propelled by higher returns from its key commodity divisions, was about 5?? times greater than last year's $US1.2 billion result.

Coal and iron ore were stand-out performers, with earnings before interest, tax, depreciation and amortisation (EBITDA) from coal up a massive 496 per cent to $US3.8 billion, and iron ore EBITDA up 62 per cent to $US9.1 billion.

Mr Mackenzie conceded BHP's entry into the onshore US shale industry was "poorly timed, we paid too much" for the assets.

"We would like to get on with the exit from shale," he said, adding that BHP would "be patient to make sure we restore value for shareholders".

The preferred method to dispose of the "non-core" US shale investment was via a small number of trade sales, although other options would be considered.

"We'll look at everything in order to decide what is the right way through this," he said.

BHP's shale announcement was welcomed by analysts and investors.

"We've always been of the view that it's not a core BHP business and it's not a tier-one asset. [And] it's a declining return business," Citi analyst Clarke Wilkins said.

"It was poorly timed, they paid too much and then they went too hard when they acquired it."

Matthew Haupt, portfolio manager at Wilson Asset Management, a BHP shareholder, welcomed the shale announcement.

"I think that's a big relief for all shareholders," he said.

"It's been a terrible investment and I think the market is relieved that they can just focus on their tier-one assets now."

Mr Mackenzie said in 2018 financial year BHP would generate strong free cash flow, while in the medium to longer term it would strengthen its balance sheet and make significant productivity gains.

"We'll grow value and returns, which remain at the heart of what we do every day. Our plan is a plan that delivers shareholder returns for decades to come," he said.

BHP declared a final dividend of 43 US cents per share, payable on September 26, for a full-year payout of 83 US cents per share. The final dividend is more than triple last year's final dividend. BHP has about 600,000 retail shareholders.

It had been a "rough time for shareholders, they've been very patient with us. And I think it's very appropriate that when we're able to do so, we reward them," Mr Mackenzie said.

"We actually have biased our free cash flow towards the pay down of debt, but we thought we should keep a little bit back to put a little bit more juice into the dividend this time, and frankly to maintain a reasonable yield on the stock."

The market reacted positively to BHP's news, with the stock climbing 28?? to $25.98.

The decision to exit US shale comes after a comprehensive review of BHP's portfolio, and amid loud calls from activist investor Elliott Management for an overhaul of the miner, including a full exit from onshore US shale.

BHP also reiterated its position on its Canadian potash project, Jansen, revealing it would not move beyond preliminary works unless it passed strict capital allocation tests.

"We are very happy that we have multiple value-creating options, which span both commodities and time frames. The Jansen project is one of those options ... we have a large resource, which has the potential to provide a low-cost, long-life, expandable mine," BHP chief financial officer Peter Beaven said.

"While timing is uncertain, we have no doubt that the world will need new potash supply. And, when it does, we believe Jansen is best placed. But, Jansen will not proceed unless it passes our strict capital allocation tests."

BHP reportedly paid about $US20.6 billion for two major US onshore acquisitions about six years ago, and has spent billions more on its US shale assets in the years since. But in its fiscal 2016 results, it included an impairment charge of $US4.9 billion against the value of its onshore US shale assets.