Shipments of Russian oil will be exempted from the US-led plan to cap the price paid for the country’s exports if they are loaded before Dec. 5 and unloaded by Jan. 19, the US Treasury Department said Monday.

The guidance addresses one of several questions from companies and investors involved in the oil trade -- what happens to shipments of Russian oil priced above the cap that were loaded before the deadline but remained en route when the regime comes into force.

Anxiety has been growing over the lack of clarity about how the US plan to cap the price of Russian oil aligns with separate European Union and UK sanctions set to take force on Dec. 5.

A Treasury official speaking on a call with reporters Monday declined to say when the coalition of countries working on the cap plan would set the price level for the program or where that level might be. US officials also didn’t offer any comment on whether the European Union will alter their sanctions in line with the US guidance to exempt shipments en route on Dec. 5 from new restrictions. 

As EU sanctions language stands, it appears such shipments could lose their insurance mid-voyage if the bloc doesn’t modify its provisions or provide guidance. 

The price cap plan was developed by the Treasury Department to work in conjunction with EU sanctions that would bar companies in the bloc from providing services to support the shipments of Russian oil anywhere in the world beginning Dec. 5. Those include trade finance, brokering and insurance.

The Biden administration has feared those measures would trap a meaningful amount of oil inside Russia, causing the global price to spike. As a workaround, the Treasury convinced Group of Seven governments, and then the rest of the European Union, to carve out an exception allowing companies to extend those services provided a cargo was priced under an agreed cap.

The plan has so far survived severe skepticism from some within the energy sector, as well as within governments allied with the US on overall Russia sanctions, but details of its implementation remain hazy as the deadline approaches.