The U.S. Treasury on Monday delisted a Russian petroleum supplier that had been sanctioned in 2017 for providing oil to North Korea, saying the company has proved it severed ties with the DPRK-linked operations.

The entities removed from Treasury’s Office of Foreign Assets Control (OFAC) Specially Designated Nationals (SDN) List were the Independent Petroleum Company (IPC) and its subsidiary AO NNK-Primornefteproduct (NNK-P).

It is the first time the U.S. has removed secondary sanctions imposed in relation to North Korea.

IPC was first designated in June 2017, with Treasury saying at the time