DETROIT — Despite praising automakers for recent gains in fuel economy, two federal agencies said on Monday that surging consumer demand for pickups and sport utility vehicles made it unlikely that the industry could meet the government’s ambitious projections a decade from now.

If fuel prices remain low, and trucks continue to outsell cars, the industry will probably not meet the goal of 54.5 miles per gallon as a fleetwide average by 2025, but will probably come in at only about 50 miles a gallon, according to a report by the Department of Transportation and the Environmental Protection Agency.

The report issued on Monday was termed a draft by administration officials, and included input from the California Air Resources Board, as well as the two federal agencies.

That lower fuel economy number would translate into higher levels of carbon dioxide emissions, which environmentalists say would make global climate change worse and undercut efforts to curtail greenhouse gases agreed to by the Obama administration in last year’s Paris climate accord.