WASHINGTON — The Interior Department on Monday gave the go-ahead for Shell Oil to begin drilling three exploratory wells in the Chukchi Sea, a move that opens the door for offshore oil and gas production in the Arctic.

"This is progress," said Alaska Sen. Lisa Murkowski, the top Republican on the Senate Energy and Natural Resources Committee, calling the announcement "an encouraging sign that Alaska's oil and natural gas resources can continue to play a major role in America's energy security."

The company's proposal calls for using several vessels, including a drill ship and oil spill response vessels, the Interior Department said. The closest proposed drill site is more than 60 miles from shore.

Shell Alaska Vice President Pete Slaiby said that his company thinks its exploration plan addresses the concerns he's heard in North Slope communities, "including concerns around program footprint and pace."

"Shell believes the Chukchi Sea could be home to some of the most prolific, undiscovered hydrocarbon basins in North America," Slaiby said.

Interior Secretary Ken Salazar called the approval by the Minerals Management Service "conditional." The agency still must comply with a court-ordered redo of an environmental sensitivity analysis, plus Shell still must obtain Environmental Protection Agency air quality permits for the vessels used in exploration. Slaiby said that the company listened to critics of its previous drilling plans in the Arctic and spent more than $25 million to tighten the air pollution controls on its drill ship, the Frontier Discovery.

Shell, Conoco Phillips and other companies in 2008 paid more than $2 billion for leases in the Chukchi Sea off the northwest coast of Alaska. The companies and state officials think the offshore reserves could power the Alaska economy for decades.

The potential offshore development remains a concern to Natives and environmentalists, however. Natives along the northern coast worry the noise of offshore development could chase away bowhead whales and other subsistence foods.

"The proposed oil and gas activities affect the very foundations of who we are as individuals and as a people," said Caroline Cannon, president of the Native village of Point Hope, Alaska. "We have a right to life, to physical integrity, to security, and the right to enjoy the benefits of our culture."

Environmentalists have a number of concerns, chiefly that there is limited technology for cleaning up oil spills in icy water.