The two sources, who spoke on condition of anonymity because the talks about a potential insolvency are confidential, said that Nord Stream 2 AG has been working with a financial adviser on clearing some of its liabilities and could formally begin insolvency proceedings in a Swiss court as soon as this week.

Nord Stream 2 AG did not respond to requests for comment from Reuters. Gazprom declined to comment.

The 1,230 km (767 mile) pipeline had not begun commercial operations because it was pending certification in Germany, which last week put this process on hold as a result of the escalating Ukraine crisis.

The U.S. Treasury Department’s Office of Foreign Assets Control issued an executive order on Feb. 23 authorising “the wind down of transactions involving Nord Stream 2 AG” or “any entity in which Nord Stream 2 AG owns, directly or indirectly, a 50 percent or greater interest” by March 2.