RIO DE JANEIRO – Brazil's Vale, the world's top iron-ore producer, forecast steady prices for the mineral and rising premiums for its top quality ore, thanks to strong demand from China and despite global trade tensions.

Vale CEO Fabio Schvartsman said a scarcity of Vale's trademark top quality ore protects the miner for the foreseeable future from the impact of a global trade war, which has hurt other minerals.

"It would take a cataclysm for this to change," Schvartsman told analysts on a conference call, a day after posting solid second-quarter results. Those results came despite a slump in Brazil's real currency and a May truckers' strike which hit growth in Latin America's top economy. Vale's shares were up 2.15% on Thursday.

Trade war declarations "have not led to any significant reduction in iron-ore prices ... Under normal scenarios, we have a very large probability that prices will be reasonably well anchored," he said.

China's campaign to clean its skies by clamping down on polluting steel mills has fueled a need for high-grade iron ore to boost productivity and limit emissions, opening the door wider for suppliers of better quality ore to the world's biggest buyer.

Though iron-ore prices slid in the second quarter, the Chinese push has helped Vale lock in rising premiums for its high quality ore, even as a trade war between the United States and China has sent copper prices to seven-month lows.

Executives also said a business plan for Samarco, a joint venture with BHP that was the site of a fatal dam burst, was being finalized and would shed light on when operations there could restart.

However, they noted resuming operations would require licenses from authorities that are beyond the companies' control.

Operations at Samarco were halted after a November 2015 dam collapse which killed 19 people and unleashed Brazil's worst environmental disaster on record. In June, Samarco, Vale and BHP signed a deal with Brazilian authorities to settle a 20-billion real ($5.35-billion) lawsuit relating to the tragedy.

Vale executives on Thursday kept a net debt goal of $10-billion after cutting debt to $11.5-billion in the second quarter. Schvartsman had previously said he hoped to reach the $10-billion target by the middle of the year.