WASHINGTON — The Obama administration may require companies drilling for natural gas on public lands to disclose the chemicals being used in a technique called hydraulic fracturing.

Officials are weighing the policy, Interior Secretary Ken Salazar said, calling hydraulic fracturing “a hot and very difficult issue” on public and private lands. Also known as “fracking,” the process involves pumping millions of gallons of water mixed with sand and chemicals underground to force open channels so natural gas will flow.

“As the nation’s largest land manager, the Department of the Interior has a responsibility to ensure that natural gas is developed in a safe and environmentally sustainable manner and protects the other valuable resources on those lands, including preventing harm to the air, water and species that call these lands home,” Salazar said Tuesday at a forum he hosted on the issue.

He said officials have yet to settle on a policy. Onshore gas wells on Interior-managed lands account for 11 percent of the nation’s natural gas supply.

President Barack Obama has expressed support for increasing the use of natural gas in an effort to reduce dependence on foreign oil and encourage cleaner fuels.

Federal regulators are taking a new look at fracking as gas drillers swarm to the lucrative Marcellus Shale beneath Pennsylvania, New York, West Virginia and Ohio and blast into other shale formations around the country.

The New York Assembly approved a temporary ban on fracking early Tuesday. The moratorium is meant to allow more time for the state Department of Environmental Conservation to issue new guideline.