The Drug Enforcement Administration was forced to suspend its operations in Peru earlier this month as a result of interference from the Peruvian armed forces, DEA chief Robert C. Bonner said yesterday.

He said in an interview that the agency's anti-drug raids would not be resumed in the Andean nation until U.S. officials are satisfied that "we can conduct operations effectively." But a U.S. Embassy spokesman in the Peruvian capital of Lima said raids had resumed in recent days at "a reduced level."

The decision to suspend U.S. operations was made by Peruvian police with DEA concurrence following a recent incident in Peru's prime coca-growing region where Peruvian soldiers blocked a team of Peruvian police and DEA agents from entering a building suspected of containing a large cache of semi-processed cocaine.

Other U.S. officials said that as a result of that and other recent developments, the State Department is now seriously considering "decertifying" Peru as a country cooperating with U.S. anti-drug efforts. Such a move would cut off most U.S. aid to Peru and require the United States to vote against any loans for Peru in the International Monetary Fund and other international institutions.

The development is a potentially damaging setback to U.S. hopes of curtailing the drug trade in Peru, whose farmers grow coca for more than half the cocaine entering the United States. In recent months, U.S. officials said, Peru's coca crop has jumped to unprecedented levels, and local trafficking of coca leaves and semi-processed coca paste surged dramatically after a temporary disruption earlier this year.

Bonner said yesterday that the Nov. 30 incident in Sion, a village in an Andean mountain valley 350 miles northeast of Lima, was "symptomatic" of problems that long have impeded DEA operations in Peru. Among them were "indications" that Peruvian military officials were selling information about upcoming DEA raids to drug traffickers in the coca-growing Upper Huallaga Valley, he said.

Bonner referred to the suspension of operations as a temporary "stand-down" and added, "We'd like to see some sign it's going to be possible to conduct operations effectively."

DEA spokesman Frank Shults said later that Bonner was not "issuing an ultimatum" to the Peruvian government. Other U.S. officials said one team of DEA agents had left Peru earlier this month in a normal rotation for the holiday season, and a new team will be dispatched to the Upper Huallaga Valley in mid-January. Any future operational decisions will depend on the Peruvian police as well as an overall assessment of DEA activities worldwide, Shults said.

The security of DEA agents in Peru has been a thorny issue for some time because the jungle-like Upper Huallaga is also a stronghold of the Maoist Shining Path guerrillas. Last year, the State Department spent $1.2 million to build a heavily fortified outpost in the village of Santa Lucia to be used as a staging ground for helicopter raids by DEA agents and Peruvian police.

For the past year, rotating teams of 12 to 15 DEA agents and State Department contractors have been sent to Santa Lucia to attack drug traffickers. But U.S. officials said the raids have been undermined by a lack of cooperation from local Peruvian military commanders, who require seven days' notice of any raids.

Last month, U.S. officials received new intelligence reports that senior Peruvian military commanders had tipped off drug traffickers to one series of DEA raids at a meeting in the village of Uchiza.

Bonner said yesterday he wants an end to the requirement for such a long advance notice. "My first and foremost concern is that it potentially endangers DEA agents that may literally walk into some trap or setup," he said. "Secondly, and more likely," he said, is the prospect that targeted drug processing laboratories may be "shut down" by the time DEA agents arrive.

The concerns came to a head Nov. 30 in the village of Sion when a team of DEA agents and Peruvian police sought to enter an eight-room building agents believed hid a cache of more than 1,000 pounds of semi-processed cocaine base. A military contingent of 20 to 25 Peruvian soldiers blocked the agents from entering for about 15 minutes, and when the agents entered, most of the cocaine base had been removed.

A State Department official said yesterday that the soldiers' interference was part of a "repeated pattern of incidents" in which the Peruvian armed forces have thwarted DEA operations and prompted new concerns about Peru's status in the State Department's annual report to Congress next month on international cooperation in the drug war. "Right now, they are not certifiable" as a helpful nation, one official said.

U.S. officials expressed these concerns bluntly to Hernando de Soto, a Peruvian economist advising President Alberto Fujimori, during a round of meetings here last week. Included on the list of problems were Fujimori's decision to turn down a $35 million military aid package and his failure to develop a law enforcement program to complement his plans to offer alternative economic assistance to the nation's coca farmers.

"We wanted to make sure that the lesson was unambiguous," one U.S. official said.