The FBI arrested a senior Soviet military attache at a remote site in Prince George's County late Thursday night after he had picked up secret documents left by a U.S. Air Force officer who was working undercover with counterespionage agents, FBI officials said yesterday.

Col. Vladimir Makarovich Izmaylov, 43, highest-ranking air force officer at the Soviet Embassy here, will be expelled from the country, U.S. officials said. Izmaylov scuffled with FBI agents on a secluded road in Fort Washington minutes after burying a milk carton with the latest installment of the $41,100 he paid the U.S. officer for military documents, the FBI alleged.

Dana E. Caro, head of the Federal Bureau of Investigation's Washington office, said Izmaylov was seeking documents on the Reagan administration's Strategic Defense Initiative research program, also known as "Star Wars," along with data on the cruise missile, Stealth bomber and a hypersonic passenger jet known as the Trans-Atmospheric Vehicle.

The espionage attempt, which had been under FBI surveillance for several months, was a classic cloak-and-dagger scheme involving high-speed cameras, code names, carefully selected "drop sites" in suburban Maryland and Virginia and cellophane that, after being chemically treated, revealed instructions to the undercover officer.

Caro praised the Air Force officer, who was approached by Izmaylov nearly a year ago, for his "courageous" conduct in helping "to thwart a significant loss of highly classified weapons to the Soviets."

The Air Force refused to release the man's identity, but sources described him as a high-ranking officer with access to top U.S. military secrets. Caro said at a news conference that the operation was run by the GRU, the Soviet military intelligence agency, which he said has been "very, very aggressive" in trying to recruit military personnel in the Washington area.

The FBI released Izmaylov to the Soviet Embassy, and State Department officials said yesterday that he has been told to leave the country and is expected to depart Sunday. Foreign diplomats are protected from criminal charges by diplomatic immunity, and the United States has expelled a number of Soviet diplomats in recent years after accusing them of espionage.

Caro said the material that the Air Force supplied to Izmaylov "did not have any value to the Soviets, although I'm sure they believed it did." But he said the FBI had learned a good deal about Soviet intelligence objectives.

The U.S. officer reported Izmaylov's first contact to the FBI and the Air Force and volunteered to work undercover, Caro said. He said the Soviets tested him for nearly a year before asking him to photograph classified documents. Izmaylov and the officer had several clandestine meetings, some of which were recorded by FBI cameras.

Under the Soviet plan, the American officer would bury Air Force documents at remote sites known as "dead drops." The Soviets would later bury a package containing cash for the last delivery and instructions on future documents and meeting places.

The U.S. officer would then visit a third location, called a "signal site," where he would leave an orange soda can or a Christmas tree ornament as a sign to the Soviets that all had gone well.

Early in their relationship, Izmaylov sent the American a picture postcard of the Capitol. "Dear DAVE," it said, "Glad you had a nice vacation. Soon I'll be in Washington, D.C. and hope to get in touch with you. Sincerely yours, Jerry SMITH."

Izmaylov gave the Air Force officer a camera for photographing papers at home and a "rollover" camera -- along with ultrathin film hidden in a standard film cartridge -- that can copy a document in the office in seconds. Izmaylov also gave him a booklet called "Beat The Box," with instructions on how to escape detection during a polygraph exam.

Izmaylov and the Air Force officer met in December at the Belle View Shopping Center in Alexandria, and the next month the American received his package near a jogging path in Mount Vernon Park in Virginia. Another drop took place in March at a hydrant near Lorton prison. In each case the Soviet material was buried in a blue container of skim milk.

Thursday night's meeting was scheduled several weeks in advance. The FBI said Izmaylov buried a milk carton with $8,000 in cash and new cellophane instructions by a telephone pole on Fort Foote Road, near Oxon Hill Road, in Fort Washington. At 10:10 p.m., the Soviet officer was arrested about a mile away in a wooded area near Riverview Road and the Federal Communications Center.

"He said that he was lost and he was looking for a fishing spot," Caro said. He said the startled Izmaylov was carrying a knife with a four-inch blade, which he did not use, but that he swung at FBI agents before being subdued.

Izmaylov's final cellophane message to his American contact, developed by the FBI, thanked him for the latest documents but said he "could not conceal some disappointment that it was not all grade 'A'." Izmaylov said the $8,000 was enclosed "in hope that you'll make an extra effort in getting info I specified in previous messages," and warned him "not to attract attention" in spending the money.

The money, the message and other spy paraphernalia were displayed before television cameras at the FBI office at Buzzards Point yesterday as bureau officials sought to publicize their counterintelligence efforts and underscore the Soviet recruitment efforts in this area.

Izmaylov, who lives at Wildwood Towers in Arlington, arrived in the United States in October 1984 after a previous four-year tour of duty that ended in 1980. He has been a squadron navigator and staff officer in the Soviet air force, U.S. officials said.

In another development, the Associated Press reported that a high-ranking Soviet spy in North Africa has been brought to the United States, a month after he walked into the U.S. Embassy in Tunisia. Sources told the news service that Oleg Agraniants, a KGB agent assigned to the Soviet Embassy in Tunisia, told U.S. officials he wanted to defect and has agreed to provide information about Soviet operations in Arab countries.