The International Atomic Energy Agency plans to ask Iraq to permit an official inspection in coming days to find out if Iraq has diverted about 20 kilos of enriched uranium to make an atomic bomb.

A State Department official and some outside experts said yesterday that Iraq probably would allow the inspection to put to rest speculation that it had assembled a bomb using uranium obtained years ago from the Soviet Union and France.

If Iraq refuses to allow the inspectors in, said David Fischer, a former IAEA official, it will be open to suspicion "that it's up to some monkey business." He called the inspection a "litmus test."

The uranium in question includes 12.5 kilograms of highly enriched uranium originally supplied for a nuclear plant that was later bombed by the Israelis and another 8 kilos supplied by the Soviets for a research reactor.

The total amount is less than the 25 kilos that the Vienna-based IAEA says is necessary for a crude atomic bomb. But given sufficiently advanced technology, a bomb could be created with the amount Iraq has.

If the uranium is being used in an above-board manner, inspectors will be able to find it. If not, "eyebrows will go up," said Fisher, who is in Washington for a conference.