Five Democrats crossed party lines and supported the ANWR drilling amendment, while eight Republicans went against their party's position and backed keeping the refuge closed.

The administration and many Senate Republicans framed the ANWR debate as a national security issue, saying the refuge's potential 16 billion barrels of oil was crucial to reduce U.S. dependence on crude from unfriendly countries like Iraq.

ANWR is roughly the size of South Carolina, sprawling over 19 million acres (7.7 million hectares), on Alaska's northeast coast. Republicans offered to keep any drilling in AWNR limited to just 2,000 acres (800 hectares) at any one time.

Majority Leader Tom Daschle, a South Dakota Democrat, said the vote was an important test of Bush administration efforts to weaken environmental protections.

"We are just not going to allow Republicans to destroy the environment," Daschle told reporters. "We believe that this is a dividing line between Republicans and Democrats, and we're willing to take it anywhere in the country. We feel that strongly about it."

Environmental groups praised the Senate vote. "It's a great victory for wildlife over (oil prospecting) wildcatters," said Mark Van Putten, head of the National Wildlife Federation.

WHITE HOUSE WANTS ENERGY BILL

President George W. Bush, a former Texas oilman, made drilling in ANWR the centerpiece of his proposed U.S. energy policy. The White House plan also encourages more U.S. production of natural gas, coal and nuclear power.

"At a time when oil and gas prices are rising the Senate today missed an opportunity to lead America to greater energy independence," White House spokesman Ari Fleischer said.

The administration may try to revive ANWR drilling in a conference committee to resolve differences between an eventual Senate energy bill and one passed earlier by the U.S. House of Representatives, Fleischer told reporters.

"The president will continue to fight for the tens of thousands of jobs that are created by opening ANWR," he said.

The Republican-led House last year approved an energy bill that would allow drilling in the refuge. If the Senate finishes a bill, lawmakers from both chambers would work out differences before a final plan could be sent to the president.

Republican Ted Stevens of Alaska said he was not giving up on ANWR drilling.

Stevens said he would offer a new amendment to allow native Americans living in ANWR the right to drill on the 92,000 acres they own. If that fails, Republicans will try to include the provision in other legislation.

"We'll be voting on energy until this Congress is over," Stevens said.

HEATED DEBATE OVER ANWR

During a two-day Senate debate on ANWR, Democrats said the refuge does not hold enough to oil to significantly reduce U.S. imports. Also, ANWR is home to polar bears, caribou and other wildlife that would be threatened by oil drilling and its heavy equipment, roads and buildings, they said.

Sens. Joseph Lieberman of Connecticut and John Kerry of Massachusetts led the Democrats' move to kill the measure. Both are expected to be Democratic presidential hopefuls in 2004.

The ANWR issue stirred heated debate.

"The so-called environmentalists are not interested in science, they are not interested in the health of the planet," said Republican Frank Murkowski of Alaska. "They know if we win ANWR - and we will some day - their chief fundraising issue goes away."

Other Republicans insisted that ANWR's oil reserves were needed more than ever because of the volatile Middle East.

"This is a great loss for American security and a big victory for (Iraq's) Saddam Hussein and other nations which sell to us their oil and export back to us their terrorism," said Republican Conrad Burns of Montana.