The U.S. government is opening the door to seismic testing on the continental shelf off the Atlantic Coast, a step that could lead to offshore drilling on the U.S. side of Georges Bank for the first time in 30 years.

Secretary of the Interior Ken Salazar announced this week that his department will look at the environmental impact of allowing such testing. He said several companies want to know how much oil and gas is off the Atlantic coast.

"We have six companies that have filed to do additional seismic work in the Atlantic, and so we will be undertaking a scoping process," Salazar said Monday.

Two of those companies have filed maps showing they intend to do seismic testing off the coast of Maine. They have yet to pass an environmental review.

Nova Scotia is watching the developments in Washington closely.

A moratorium on testing and drilling on the Canadian side of Georges Bank — a rich fishing ground southwest of the province — expires on Dec. 31, 2012. Several scientific studies are underway to help federal and provincial politicians decide whether to lift the ban.

Sandy MacMullin, the province's acting deputy minister of energy, said the U.S. review doesn't necessarily mean exploration will proceed.

"It's not a carte blanche that seismic will be allowed to occur," he said.

MacMullin said both the Nova Scotia and federal governments must decide by the end of July whether there will be a public review on the moratorium.

He said the announcement by the U.S. government will have no bearing on what the federal and provincial governments decide to do on their side of Georges Bank.