Iraq could build a nuclear bomb in a few months if it obtained radioactive material, and its arsenal contains powerful chemical and biological weapons that can be quickly mass produced, according to a report Monday.

Developing weapons of mass destruction is one of Iraq's top priorities, and Saddam Hussein devotes enormous resources to such weapons, the report by the International Institute for Strategic Studies said.

"War, sanctions and inspections have reversed and retarded, but not eliminated, Iraq's nuclear, biological and chemical weapons and long-range missile capacity, nor removed Baghdad's enduring interest in developing these capabilities," said the institute's director John Chipman.

Left unhindered, it "seems likely that the current Iraqi regime will eventually achieve its objectives," the report said.

State Department spokesman Richard Boucher said the report jibed with U.S. information, saying that when inspectors left in 1998 it was known that not all Iraq's biological and chemical weapons stocks had been destroyed.

"I think we have every bit of evidence to conclude that Iraq had programs, they were partially destroyed, and they've tried to maintain and expand them since the inspectors were gone," he said in Washington.

"As those programs continue, it may not be possible to predict exactly when they might reach fruition, but one has to deal with the problem sooner rather than later."

The report, compiled by a range of experts, focused particular concern on Iraq's efforts to develop nuclear weapons. It expressed concern that a nuclear weapon, if developed, could fall into the hands of terrorists.

Although Baghdad appears several years away, at least, from making its own nuclear or fissile material for a bomb, it could get the material from a foreign source and construct a weapon quickly, the report said.

"If, somehow, Iraq were able to acquire sufficient nuclear material from foreign sources, it could probably produce nuclear weapons on short order, probably in a matter of months," the report said.

The report gave no evidence that Iraq has been able to obtain nuclear materials. There has been concern about nuclear material being sold on the black market in parts of the former Soviet Union.

Iraq retains significant biological and chemical weapons and, more importantly, the ability to quickly produce more stocks, the report said.

Iraq probably possesses hundreds of tons of chemical weapons or agents for their production, including mustard and sarin gas, the report said.

On biological weapons, Iraq could have large stocks of biological warfare agents, including, possibly, thousands of gallons of deadly anthrax, the report said.

The report, presented as an impartial and technical analysis, echoed similar warnings from various government and private analysts and did not appear to contain much new information.

"There's a tremendous unknown," one of the authors, Gary Samore, told a press conference.

Prime Minister Tony Blair's office welcomed the report, but said it would soon publish its own dossier on Iraq's weapons program, containing intelligence information not available to the report's authors.

The institute report said that while Iraq has significant weapons of mass destruction, the threat is diminished by its limited ability to deliver them.

It probably has about 12 missiles with a range of 400 miles, but lacks the technology to use them to deliver nuclear weapons, if they are ever acquired, the report said. A nuclear weapon could be delivered by a plane or commandos, it said.

The missiles with a 400-mile range "could hit Saudi Arabia, Kuwait, Israel, Iran, Turkey," said Chipman.

Similarly, Iraq's ability to deliver chemical and biological weapons is limited, mostly dependent on a few old planes and missiles. But the weapons could pose a threat to U.S. and allied forces and civilians in the region in the event of a war, it said.

The United States has been calling for action to stop Iraq's efforts to build weapons of mass destruction, saying Baghdad poses a threat to U.S. and international interests.

The report said attacking Iraq risks incurring Iraqi retaliation with weapons of mass destruction, but doing nothing risks allowing Baghdad to develop more weapons.

"Either course of action carries risks. Wait and the threat will grow. Strike and the threat may be used," it concluded.