WASHINGTON (AP) _ A military affairs expert says there is good reason to believe that Iraq and Syria possess biological weapons, and Israeli officials confirm that Iraq is close to creating such an arsenal while Syria is in the research stage.

''There is strong evidence to suggest that Iraq has biological weapons, possibly including toxins,'' W. Seth Carus, a researcher at the Washington Institute for Near East Policy, said Tuesday.

Carus, who has been studying the proliferation of chemical and biological warfare in the Middle East for the past several years at the privately funded think tank, said reports from Iran that Iraq used biological agents against its Kurdish minority are unreliable.

But he added he had been informed by official sources that Iraq does have such capability. Iraq produces the weapons at a facility near the village of Salman Pak, 35 miles southeast of Baghdad, ABC News reported Tuesday, citing unnamed intelligence sources.

Iraq also has the capacity to make 1,000 tons of chemical agents annually, Carus said. There is documented proof Iraq used such weapons as mustard and nerve gas against Iran and against the Kurds as recently as 1987. Syria manufactures chemical weapons but has never used them, Carus said.

Syria also has a stock of biological arms, but it is not known if it has acquired sophisticated delivery systems such as rockets, Carus said. Syria may have received help for its program from communist North Korea, which is known to have a biological warfare program, Carus said.

Israeli officials said, however, that Iraq had completed research and development on such weapons and was ''on the verge'' of manufacturing them. Syria is in the initial stages of research, said the officials, who spoke only on condition they not be named.

Toxins, such as snake venoms, are poisons which are not biological agents but can easily be produced by using bacteria cultures. Biological weapons are living organisms that cause lethal diseases such as cholera, anthrax and typhoid. They can be introduced into water systems or simply sprayed into the air.

Iraq, which signed but did not ratify the 1972 biological weapons treaty, denies having biological or chemical arms.

A State Department official declined to say if the United States is aware of the Iraqi capability.

Egypt is believed to have worked on acquiring biological weapons in the 1960s, Carus said. In the early 1970s, the late Egyptian President Anwar Sadat said ''we have the instruments of biological warfare in the refrigerators.''

But Egypt did not use the germs in its 1973 war with Israel or in any other conflict, Carus said.

Israel has the ability to produce biological agents, ''although it may not currently have a biological warfare capability,'' Carus said. Iran has said it intends to acquire such capability, but little is known about that plan, he added.