The U.S. Energy Information Administration said an oil import tracking tool is meant to assess the impact of a "possible relaxation" of export restrictions.

U.S. crude oil imports have declined steadily since 2010, as output from domestic shale basins increase. In a weekly petroleum report, EIA said U.S. oil production was around 9 million barrels per day.

EIA said in a brief announcing the oil import tool it's meant highlight the internal market response to growing domestic crude oil production.

"It is one part of EIA's ongoing effort to assess the effects of a possible relaxation of current limitations on U.S. crude oil exports, which is another avenue to accommodate domestic production growth," the administration said in its Thursday brief. "EIA is undertaking further work on this larger question, and expects to issue more analysis reports over the coming months."

U.S. legislators restricted crude oil exports in response to the oil embargo from Arab members of the Organization of Petroleum Exporting Countries in the 1970s. There are no limitations of the export of petroleum products like gasoline and, more recently, some companies have started exporting an ultra-light form of domestic crude oil called condensate.

Australian company BHP Billiton in early November said it was the one that concluded condensate taken from the Eagle Ford shale play in Texas was legally eligible for exports.

The crude oil export debate in the United States has sparked reactions from the domestic upstream, or exploration and production, and downstream, or refining, sectors.

George Baker, executive director of the Producers for American Crude Oil Exports, said multiple studies have shown lifting the ban would have widespread economic benefits.

Thomas O'Malley, executive chairman of refining company PBF Energy, said the "only logistical conclusion" to make if the ban were lifted is that oil prices will increase, refiners will reduce gasoline production in response and prices at the pump will increase.

U.S. government and policy center studies have shown there would be some consumer benefits from easing the restrictions, though each found lifting the ban did little to eliminate crude oil imports.

U.S. Energy Secretary Ernest Moniz said crude oil export rules are under review.