"All transactions and activities prohibited by ... [current sanctions] where the only government of Venezuela entities involved are Nynas AB or any of its subsidiaries, are authorized through 12:01 a.m. eastern daylight time, April 14, 2020," the notice said.
Nynas is a 50-50 joint venture between the Finnish company Neste Oil and Venezuela’s state-owned PDVSA, which the US has previously sanctioned.
In June, the Treasury Department issued a license allowing limited transactions with Nynas, but that measure was set to expire on October 25.
The United States has in recent months ratcheted up sanctions on Venezuela as part of its campaign to oust President Nicolas Maduro and install opposition leader Juan Guaido as his successor. Maduro has accused Guaido and Washington of collaborating to orchestrate a coup to take control of Venezuela's resources.