Obama bans new oil, gas drilling off Alaska

US President Barack Obama on Tuesday banned new oil and gas drilling in federal waters in the Atlantic and Arctic Oceans, in a push to leave his stamp on the environment before Republican Donald Trump takes office next month.

Obama used a 1950s-era law called the Outer Continental Shelf Act that allows presidents to limit areas from mineral leasing and drilling. Environmental groups said that meant Trump's incoming administration would have to go court if it sought to reverse the move.

The ban affects 115 million acres (46.5 million hectares) of federal waters off Alaska in the Chukchi Sea and most of the Beaufort Sea and 3.8 million acres (1.5 million hectares) in the Atlantic from New England to Chesapeake Bay.

Trump, who succeeds Obama on Jan 20, has said he would expand offshore oil and gas drilling. A recent memo from his energy transition team said his policy could increase production in the Chukchi and Beaufort Seas, as well as the mid- and south Atlantic.

A Trump representative did not immediately comment on the announcement.

Even if Trump tries to fight the move, few energy companies have expressed a desire to drill anytime soon off the coasts thanks to abundant cheap shale oil in North Dakota and Texas.

Exploratory drilling in the Arctic is expensive and risky. Shell Oil ended its quest to explore in harsh Arctic waters in 2015, after a vessel it was using suffered a gash and environmentalists uncovered a law that limited its drilling.

The American Petroleum Institute oil industry group disagreed about the permanence of the ban and said Trump could likely use a presidential memorandum to lift it.

"We are hopeful the incoming administration will reverse this decision as the nation continues to need a robust strategy for developing offshore and onshore energy," said Erik Milito, API's upstream director.

The White House and Canadian Prime Minister Justin Trudeau jointly announced their move to launch "actions ensuring a strong, sustainable and viable Arctic economy and ecosystem".