U.S. intelligence sources have reported that Iraq has produced a stockpile of biological weapons and will have a "militarily significant number" of them ready for battlefield use in a few months, adding a dangerous new threat to the Middle East, according to intelligence and congressional officials.

The U.S. forces in the Persian Gulf, now numbering about 160,000, are equipped with protective gear against chemical attack, but many officials say the suits and gas masks are not adequately effective against biological agents.

Iraq's new biological arsenal is reported to include weapons that can disperse respiratory anthrax, an airborne form of a disease that causes hemorrhaging in humans and cattle and is often fatal if not treated.

Details of the intelligence report were disclosed by Rep. Les Aspin (D-Wis.), chairman of the House Armed Forces Committee, who said the report will be an "added ingredient" in the Bush administration's timetables for consideration of any military action against Iraqi forces.

Aspin, speaking at a breakfast meeting with reporters, added that although no final decision has been made, recent discussions between President Bush and the congressional leadership indicate there is "more and more evidence that the administration is looking more favorably on an 'early war' option."

However, a senior administration official said yesterday, "Their {Iraq's} military capability -- including biological weapons -- has always been part of the debate, but that capability alone is not driving any decision."

Aspin revealed new details of intelligence findings just days after Central Intelligence Agency Director William H. Webster publicly said for the first time that Iraq has "a sizable stockpile" of biological weapons. While administration and Defense Department officials have extensively discussed Iraq's potential use of chemical weapons, until the past few days they have refused to detail Iraqi President Saddam Hussein's biological warfare capabilities.

Said Aspin, "Saddam Hussein . . . is expected to have a militarily significant biological program by the end of this year or early next year. This will be a new dimension to the problem. It is a more important and more serious element than the chemical threat. It is a harder thing to deal with."

Officials said that Iraq had worked intensively the past two years to develop a biological weapons program, and by early next year should be able to produce and amass large numbers of the weapons, which would pose far more serious threats to U.S. troops and civilian populations in Saudi Arabia than Iraq's already potent chemical warfare capabilities.

Intelligence reports state that the biological weapons can be loaded on many of the same weapons that can carry chemical warheads, including artillery shells, bombs, rockets and potentially on Scud-B missiles. Officials noted, however, that U.S. intelligence sources have no evidence to indicate that Iraq has tested either chemical or biological weapons on the Scud surface-to-surface missile. Iraq used Scuds against Iran in the "war of the cities" offensive of the Iran-Iraq war.

Biological weapons are considered potentially a more deadly threat against humans than chemical weapons because their product can be delivered covertly with little chance of detection and can linger in the atmosphere for years. By contrast, chemical weapons have an almost immediate effect on the body and tend to disperse quickly in the wind and become impotent.

The Soviet Union, Israel, Syria and other nations have done extensive research into biological agents.

The aerosol anthrax reported in the Iraqi arsenal "is awful," said Gary Milhollin, director of the Wisconsin Project on Nuclear Arms Control, which also has extensively examined chemical and biological warfare. "It poisons your blood. You have 70 to 80 percent fatalities in untreated cases." But military experts also note that biological weapons have many major limitations.

"Their effects are delayed, they are difficult to control and it is difficult to predict how much damage they will do," Milhollin wrote in a report to be released soon.

They are most effectively used as "terrorist weapons" against urban and settled populations and would likely be less effective in stopping large numbers of widely dispersed troops because of the time lag between dispersal from a warhead to the moment when they affect the body, officials said.

Milhollin added, "However, they are also difficult to defend against, and U.S. military planners are reported to be concerned that biological agents could penetrate American soldiers' chemical warfare protection suits and infiltrate the ventilation systems of ships in the Persian Gulf."

Officials also note that production facilities for biological weapons are difficult to locate because they can be produced in virtually any pharmaceutical laboratory. One of the largest production facilities in Iraq is believed to be at Salman Pak south of Baghdad.