Pilbara iron ore shipments, on a 100% basis, rose by 5% year-on-year to 80.3 million tonnes, just below UBS' estimate of 80.8Mt.

Shipments were down 11% quarter-on-quarter.

Rio said it benefitted from productivity improvements and fewer weather disruptions during the March quarter.

Rail productivity continues to improve with 85Mt railed during the period. Around 65% of trains are now in autonomous mode.

Guidance was maintained at 330-340Mt.

Mined copper output jumped by 65% to 139,300 tonnes following last year's Escondida strike, below UBS forecasts of 143,000t.

Aluminium production dropped by 5% to 800,000t due to disruptions in Canada, while bauxite production rose by 12% to 12.7Mt due to operational improvements.

Rio Tinto CEO J-S Jacques said the company delivered a solid operational performance across most commodities for the quarter.

"Our world-class Pilbara iron ore assets continue to demonstrate flexibility and the benefits of increased productivity, and production at our bauxite and copper assets was also higher," he said.

"We announced US$5 billion of divestments in the quarter, highlighting our ongoing drive to strengthen the portfolio and raise return on assets.

"By continuing to advance our mine-to-market productivity program, whilst maintaining our focus on the disciplined allocation of cash, we will continue to deliver superior returns to our shareholders."

Pre-tax and pre-divestment exploration and evaluation expenditure for the quarter was $101 million, up from $78 million in the same quarter of last year.

The company was active in 16 countries across eight commodities.

Shares in Rio rose by 0.8% to A$78.77.