In its rush to go home for the Christmas holidays, Congress created a new "drug czar" with extensive powers to set priorities and to order involvement by many government agencies in the war against illegal drugs.

The new official, proposed originally by Sen. Joseph R. Biden Jr. (D-Del.), would be appointed by the president with the concurrence of the Senate and would be a Cabinet-level appointee. The person would have the power to order other Cabinet officials, including the attorney general, the secretary of defense and others involved in drug enforcement, to follow his priorities.

The administration has opposed the concept, arguing that it creates another layer of "bureaucracy" in drug enforcement. Some congressional aides said yesterday they feared it would just cause confusion.

The drug czar was included in a crime bill that would make it easier for federal prosecutors to seize the assets of drug smugglers and increase the fines that can be levied against drug dealers.

Attorney General William French Smith said yesterday that the administration's new assault on organized crime and drug trafficking will begin just after New Year's Day following Congress' approval this week of $127.5 million in start-up money.

In a statement released here, he said the 12 new task forces covering most of the country will target three or four major cases in their regions involving narcotics trafficking by organized crime groups.

Francis M. Mullen Jr., head of the federal Drug Enforcement Administration, said that in additional to traditional organized crime families, the task forces will also target high-level drug crime involving Colombian and Mexican groups as well as outlaw motorcycle gangs.

Federal law enforcement agencies plan to hire 1,260 new investigators and 200 prosecutors with the task forces fully operational by Aug. 1.

In a speech yesterday, Smith also said he is considering setting up a "Critical Technologies Task Force" in California to deal with the problem of theft of U.S. technology by countries such as the Soviet Union.

"The Soviets' need for technology is inexhaustible," he said in a speech to the Commonwealth Club of San Francisco. "Since the beginning of its experiment in terror, the government of the Soviet Union has coveted American know-how. And in recent years as their own technological shortcomings have become apparent, they have proven themselves exceedingly adept at stealing what they covet."

The task force would use the resources of federal agencies, including the FBI, the Customs Service and the IRS, to keep watch over the more than 2,700 companies in California that deal with classified information.