WASHINGTON, Oct 25 (Reuters) - The U.S. Interior Department said on Wednesday it will hold a lease sale for land in a federal reserve in northern Alaska to oil and gas drillers, the largest number of tracts ever offered from the reserve.

The sale, to be held on Dec. 6, will involve 900 tracts in part of the Indiana-sized mass of public land known as the National Petroleum Reserve-Alaska (NPR-A). The federal government set aside the public lands in 1923 when the country was converting Navy vessels to run on oil instead of coal.

The sale is the latest move by the administration of President Donald Trump, a Republican, supporting his pledge to make the United States “energy dominant” by boosting output of oil, natural gas and coal.

On Tuesday, the Interior Department said it will hold its largest offshore auction to energy companies to date in March 2018. Nearly 77 million acres offshore Texas, Louisiana, Mississippi, Alabama and Florida will be on offer.

Republicans are eager to open Alaska’s Arctic to oil and gas drilling, but it is uncertain how much energy companies, which are enjoying a drilling renaissance in the continental United States, are willing to invest in production in the frigid north.

In the last NPR-A lease sale, in 2016, 67 of 145 available tracts received bids from energy companies, which raised nearly $19 million.

The U.S. Geological Survey said in 2010 that the NPR-A holds about 896 million barrels of undiscovered oil. A further 200 million barrels has been discovered in areas that have been explored.

The reserve also contains large amounts of natural gas.

Environmentalists have been critical of drilling in the Alaskan wilderness. Last week, Democrats in the U.S. Senate failed to block a move that could open the state’s Arctic National Wildlife Refuge to drilling.

The NPR-A sale “reflects the current administration’s wholesale approach to turning over America’s public lands to the highest bidders for development,” said Nicole Whittington-Evans, the Alaska regional director for the Wilderness Society. (Reporting by Timothy Gardner, Editing by Rosalba O’Brien)