West Germany should allow antitank fortifications to be built on its soil or reimburse the United States for the expense of piling troops and weapons near the front to slow an attack by Warsaw Pact forces, Sen. Carl Levin (D-Mich.) said yesterday.

Levin, a member of the Armed Services Committee, said that if Bonn refuses to build the tank obstacles and fortified gun positions to blunt an attack, he will push legislation designed to break the impasse.

One possibility, he said in an interview, is to withdraw some U.S. troops from West Germany. Levin said he will not resort to such pressure until he receives a report from Defense Secretary Caspar W. Weinberger on the consequences of the "no-barrier" strategy in West Germany. The Senate committee's fiscal 1987 authorization bill for the Pentagon requires Weinberger to submit the report by Feb. 27.

NATO Commander Gen. Bernard W. Rogers has told Levin that West Germany was given authority over barrier construction under the Central Regional Barrier Agreement negotiated between Bonn and nations with forces along the central front of the NATO line.

"While tactical considerations," such as storing barrier materials in the likely avenues of attack but not erecting them in peacetime, "and allied agreements are the primary reasons for a lack of fixed barriers and fortifications," Rogers wrote Levin, "two political issues would also have to be dealt with before construction of barriers in peacetime could begin.

"Those issues are the reunification of the two Germanys and the symbolism that barriers would portray and the perception/fact that barriers would deny the populace access to already limited terrain and scar the landscape."

Levin said he does not find Rogers' arguments convincing. The senator said barriers would deter a Warsaw Pact attack, save lives if an attack were launched and perhaps turn the tide by providing reinforcement time.

By barriers, Levin said he is referring to tank defenses such as cement obstacles and ditches, fortified gun positions, and command centers and hospitals in structures that could withstand bombardment.

They "are long overdue; the military knows it," Levin said. "The psychological impact of barriers would be the reassuring one that we're not going to rely on nuclear war, we're going to rely on conventional means and legitimate conventional means. There's no reason we shouldn't rely on tank barriers except for this internal political problem we've got" in West Germany.