Public joint-stock company Ukrnafta has increased its tax debt by 21.2% or UAH 2.1 billion since early 2016, to UAH 12 billion, Ukrnafta Head Mark Rollins said at a press conference in Kyiv on Wednesday.

"As of September 30, 2016, the company's tax debt grew by UAH 2.1 billion, to UAH 12 billion due to growth of the debt of some partners of the company and due to low oil prices that restricted the company's revenue. The company is holding talks to return overdue debt," he said.

Rollins said that Dniproazot chemical company has a large rise in its debt.

"The acutest issue is to return the debt by Dniproazot. A dialog to restructure it is being held," he said.

He said that the company seeks to change the cooperation system with Dniproazot.

Rollins said that the company is actively working to collect old debts from other contractors.

Ukrnafta in July 2016 filed several claims to return the debt of UAH 7.6 billion. In September two claims were upheld by lower courts of jurisdiction, he said.