The US Senate has voted down an attempt to ban oil drilling in Alaska's Arctic National Wildlife Refuge.
Alaska's Arctic National Wildlife Refuge covers 19 million acres
Senators narrowly rejected a Democratic attempt to halt the plan, which President Bush supports.
Supporters of the drilling say access to the estimated 10bn-plus barrels of crude oil would cut US reliance on imports, create jobs and raise revenue.
But opponents say it would threaten a key habitat for migratory birds, polar bears, caribou and other animals.
The drilling plan, which has already survived one attempt to halt it, is part of a federal budget-cutting bill. Correspondents say it may yet fail to clear both houses of Congress.
Senators also voted overwhelmingly to prohibit exporting any of the oil pumped from the region.
The US has to import almost three out of every five barrels of oil it consumes.
President George W Bush praised the Senate for backing a "common sense approach" to improving the US energy situation.