Vale SA CEO Fabio Schvartsman said he has achieved the target of halving the company's net debt to US$10 billion, and will now focus on boosting shareholder returns, the Financial Times reported Oct 11.

"There is nothing more that can or should be done," he stated, noting that share buybacks were the best investment the company could make at this time.

"Our stock is still very under appreciated. There is still a lot to be recognized by the market," he added.

China's efforts to reduce excess capacity in its sprawling steel industry and clean up its environment has boosted demand for Vale's high grade, low impurity iron ore.

It has also lifted results and helped Vale reduce debt. The company reported EBITDA of US$3.9 billion, up from US$2.7 billion in the prior year, and reduced net debt by US$3.4 billion in the three months to June.

Aided by a new dividend policy and a US$1 billion share buyback, shares in Vale have risen 40%.

The company, while best known for its iron ore business, is also the world's biggest producer of nickel.

"Nickel is a tremendous opportunity for the future because of electric cars," Schvartsman noted.

One of the biggest challenges in Vale's nickel business is its Goro project in New Caledonia. The company is seeking for a partner to help share the cost of a new US$500 million storage area for waste at Goro.

Schvartsman has said that he will only in invest in projects that generate good returns for shareholders at current commodity prices, according to the report.

He also added that Vale expects to restart production at the Samarco iron ore mine in 2020. The mine has been shut since 2015 following a dam burst, killing as many as 19 people.