United States Steel Corp. said it is close to filing several anti-dumping complaints with U.S. authorities, adding it is still having to consider idling more plants because of difficult market conditions.

The Pittsburgh-based company has idled facilities in Indiana, Illinois, Alabama, Texas, Ohio and Arkansas this year. It gave ‘WARN’ notices to 9,000 employees earlier this year, but has so far laid off only about 2,700 employees, meaning 6,300 could lose their jobs if market conditions don’t improve.

U.S. Steel has said it plans to idle its 2,080-worker steel mill in Granite City later this month.

“The surge in imports is unprecedented. It’s no longer a matter of if we’re going to file, it’s a matter of when,” Chief Executive Mario Longhi told Reuters in London.

The U.S. steel industry is under huge pressure this year from cheap imports, a strong dollar, and from falling oil prices, which have decimated demand for steel tubes used by the oil and gas industry.

According to the American Iron and Steel Institute, importers supplied 31 percent of the U.S. steel market in April, versus just 20 percent a year ago. U.S. steel prices have dropped 21 percent this year.

“We are very diligently adjusting production to (meet) demand. We could see more plant closures,” said Longhi.

About 15 percent of U.S. Steel’s output involves making steel tubes, known as oil country tubular goods, for the oil and gas industry, but that unit is fully supplied with raw product by another U.S. Steel unit.

“For us its a double whammy. We’re not really producing any tubular goods at the moment,” said Longhi.

Moody’s lowered its outlook for the U.S. Steel sector to negative this month, saying selling prices have fallen rapidly this year to levels that will negatively affect steelmakers’ profitability.

Meanwhile the battle to rebuff imports continues.

This month alone, U.S. steelmakers formally complained about Chinese producers circumventing import duties on steel plate, while the Commerce Department found dumping of welded line pipe from South Korea and Turkey.

U.S. steel producers demanded this month that the Commerce Department scrap a trade deal sparing Russian producers of carbon steel plate from import duties.

“I’d expect (U.S. steel) production grows no more than 2 percent this year, and consumption (grows) about 2 percent. The market would be balanced without imports,” Longhi said.