WASHINGTON -- The Obama administration asked Congress on Wednesday to sell off or demolish more than 12,000 government-owned or leased properties, saying they are under-utilized or no longer needed.

The White House recommended the creation of a seven-person independent commission of property experts that would determine how to get rid of the properties. They include warehouses, office buildings, storage facilities, laboratories and unused roads.

The move to sell off government land comes as President Obama and congressional Republicans are debating ways to slash deficits expected to average more than $1 trillion annually over the coming decade. If enacted, the plan would use 60 percent of the savings to pay down the deficit and 40 percent to cover costs for other government-run facilities.

Taking the properties off the federal government's books would save $15 billion over three years, administration officials said. The federal government is the largest land owner in the United States.

It owns more than 1 million properties and has an annual operation and maintenance budget running more than $20 billion.

"Most of these properties have little or no market value," said Jeffrey Zients, the deputy director of the Office of Management and Budget. "But the ones that do, we will sell. Disposing of all of the properties, whether they have value or not, is important to do so taxpayers no longer pay for energy and maintenance costs."

There are legal hurdles, including more than 20 federal laws in place that regulate how and when a property can be sold. Many federal agencies also can't afford the short-term costs to sell the property, including moving and transaction expenses.

The proposed review commission would be modeled after the Defense Department's Base Realignment and Closure Commission, which was created in 1988 to close unneeded military installations.