MOSCOW (AP) _ The newspaper Izvestia on Monday accused Nicholas Daniloff of using a journalist's cover to ferret out military secrets about Afghanistan and claimed the American reporter worked with an alleged CIA agent in Moscow.

The government newspaper said the imprisoned correspondent for U.S. News & World Report was charged by a military prosecutor with espionage under a law that imposes penalties ranging from seven years in prison to death.

The article elaborated on accusations already made against Daniloff and expanded the charges against the reporter beyond the scope of the original claim that he received secret documents during what was described as a secret meeting with a Soviet in a Moscow park.

The arrest of Daniloff and the espionage charges filed Sunday by Soviet authorities have provoked a sharp reaction in Washington. Reagan administration officials have said the United States views the case as ''a matter of utmost seriousness'' that could effect Soviet-American relations.

The Soviet Union intervened in Afghanistan in 1979 and there are more than 100,000 Red Army troops in the country.

Ruth Daniloff, who was scheduled to to see her husband Tuesday for the third time since his arrest on Aug. 30, called the Izvestia article ''preposterous.''

''It's absolutely crazy,'' she said. ''It's just for domestic consumption while this case is being decided on a much higher level.''

Izvestia tried to link Daniloff to Paul Stombaugh, a U.S. diplomat accused of being a CIA agent and expelled from the Soviet Union in June 1985.

It cited as evidence a note, allegedly given to a Soviet by Stombaugh, that said: ''We would like to assure you that the letter delivered by you to the journalist on Jan. 24 got to the designated address.''

Izvestia claimed Daniloff was the journalist mentioned in the letter.

Daniloff has been held in Moscow's Lefortovo prison since he was grabbed by eight KGB agents in a Moscow park. He told his wife he was picked up after a Soviet acquaintance named ''Misha'' gave him a packet purportedly containing press clippings but actually filled with maps marked secret and military photographs.

Izvestia said Daniloff was handed the indictment on Sunday at Lefortovo and required to sign it, which the paper said he did reluctantly.

In a telephone call to his office from prison on Sunday, Daniloff said he could be held six to nine months without a trial. He said he was told he is not yet entitled to a lawyer.

Izvestia asserted there was enough evidence against Daniloff ''to affirm that, being connected with U.S. special services, he was engaging in espionage by their orders and under the status of a foreign correspondent in the Soviet Union, collecting by various means secret information for use in a way that damages the national interests of the Soviet Union.''

The charges appear to be based on the package handed to Daniloff and on accusations attributed to Misha that Daniloff tried to gather intelligence on the Soviet military in Afghanistan.

Izvestia said Misha was detained at the same time as Daniloff, but it did not say whether he also was being charged or identify him further. Mrs. Daniloff has said she believes the KGB forced Misha to set up her husband.

Western journalists routinely meet sources and acquaintances in parks and other public places because many Soviets are fearful of going to reporters' apartments and the apartments may be bugged.

The Izvestia account made it clear that Daniloff was followed from his apartment, describing how he ''paced back and forth'' near a subway station entrance waiting for Misha.

Izvestia said the package Daniloff received contained 26 black-and-white photos of Soviet military equipment and soldiers, a map of Afghanistan with hand-written markings showing deployment of Soviet military units, and a hand- drawn diagram of the location of other military bases.

The paper quoted Misha as saying he met Daniloff in 1982 in Frunze, the capital of Soviet Kirghizia in Central Asia near the border with Afghanistan.

The paper quoted Misha as saying: ''I became convinced that the journalist from U.S. News & World Report was not exactly what he represented himself to be.''

Izvestia claimed Daniloff asked Misha to get lists of Soviet units bound for Afghanistan, obtain pictures of Soviet military hardware used there, and find names and addresses of soldiers who served there.