Federal efforts to halt illegal drug smuggling haven't been successful because "Americans want drugs and they are willing to pay a high price to get them," says the nation's comptroller general.

Charles Bowsher says it is time "to reassess federal drug abuse policy and strategy" and the goal should be decreased demand rather than increased efforts to halt the supply.His assessment came as the Senate began work on a bill that would provide the death penalty for large-scale drug dealers whose organizations are involved in killing policemen. The Senate was scheduled to vote on a motion Thursday to conclude debate on the bill.

Bowsher's pessimistic message came in testimony to the Senate Armed Services Committee, which is holding hearings on proposals to increase the role of the military in drug interdiction efforts.

The House last month voted to have President Reagan order the Pentagon essentially to seal U.S. borders against drug traffickers. The Senate's anti-drug measure didn't go as far, but it would give new power to the Navy to arrest drug traffickers seized in international waters.

The proposals were attached to separate Pentagon budget bills approved by the two chambers. A House-Senate conference committee will resolve the differences.

Sen. John Warner, R-Va., noted the increasing chorus of congressional demands for action to halt the nation's drug problem. "Congress is on a stampede and we need some direction," he said. "We need to try to corral this stampede and point it in the right direction."

Using the military isn't the right direction, said Bowsher, who heads the investigative arm of Congress, the General Accounting Office.

"I do not suggest that efforts to control the supply of illegal drugs are useless and should be reduced," he said. "I do suggest, however, that the Congress and the executive branch should exercise great caution before deciding to devote more resources and more emphasis to supply-reduction programs."

From 1977 to 1987, federal drug interdiction efforts increased by 1,500 percent, he noted.

But "if we measure success by the number of drug users and the amounts of drugs being smuggled into our country, we must unfortunately conclude that our present strategy and policies are not working," he said.