Dollar Tree said it will close about 1,000 of its Family Dollar  stores after suffering a significant quarterly loss.

Dollar Tree, which owns Family Dollar, on Wednesday announced that it will shutter 600 of its Family Dollar stores in the first half of the year as part of its portfolio optimization. An additional 370 stores will close once their leases expire, the company said in its fourth-quarter earnings report.

In addition, 30 Dollar Tree locations will also close as their leases expire.

The company suffered a net loss of $1.71 billion in the three-month period.

Dollar Tree acquired Family Dollar in 2015 and operates more than 15,000 stores across its portfolio, including its more recent combo store format of Family Dollar and Dollar Tree stores in rural communities, according to its website.