Environmentalists sued earlier this year to block the proposed mine, arguing that it could threaten sage grouse habitats and that the former President Donald Trump's administration erred when it approved it in January.
For the first four months of the year, the market was in a 69,000 tonnes surplus compared with a 110,000 tonnes surplus in the same period a year earlier.
Steel producers in China's Jiangsu, Fujian and Yunnan provinces were told to cut production as the country aims to keep its annual output no higher than it was in 2020.