The U.S. government is threatening to sue PacifiCorp, a unit of Warren Buffett’s Berkshire Hathaway, to recover nearly $1 billion in costs related to the 2020 wildfires in southern Oregon and northern California, though the company is trying to negotiate a settlement.

The potential lawsuits were disclosed in an annual report filed by PacifiCorp’s Iowa-based parent company, Berkshire Hathaway Energy, on Monday — two days after Buffett lamented the disappointing results at the conglomerate’s utility division in his annual letter to Berkshire Hathaway shareholders. This new liability comes after the utility already agreed to pay hundreds of millions of dollars in lawsuits related to the fires.

In its annual report, Berkshire Hathaway Energy said the U.S. Justice Department told the company it is seeking $625 million in firefighting and cleanup costs related to the September 2020 Archie Creek and Susan Creek fires. Oregon’s Justice Department said it is also seeking $109 million in damages related to those fires.

In addition to that, the U.S. Forest Service has asked PacfiCorp to pay $356 million for firefighting costs and damages related to the Slater Fire that started in California but also crossed over the border into Oregon.