"We will execute the idle of UTAC in a manner to ensure that we can promptly bring production back as soon as the level of demand from our clients justifies that," CEO Lourenco Goncalves told analysts during the company's second-quarter earnings calls on 29 July.

Goncalves said the idling is to be completed by the end of August. And as a result, 420 people are to be laid off, according to the Duluth News Tribune. The newspaper said the company employed about 500 at its mine in Evelth and processing center in Forbes.  

Cliffs has reduced its 2015 forecast for its U.S. iron ore sales by 1.5 million tons to 19 million tons, again blaming the supply glut of taconite created by heavy steel imports, the newspaper said.

Goncalves told analysts that signs are beginning to show that a reduction in imported steel may occur in the latter half of this year, opening the door to an ensuing domestic production increase. And with that, the company expects to see improved demand for its iron ore.

“Our worst days are likely behind us," Goncalves said. “As actions are taken to combat the influence of unfairly traded steel in the United States, we expect to see improved industry operating conditions and profitability in the second half of this year.”