Australia's foreign minister has warned that the proliferation of weapons of mass destruction poses the greatest global security threat.

Foreign Minister Alexander Downer told a security forum in Jakarta Wednesday that terrorists are trying to obtain weapons of mass destruction.

"I think we have to face up to the fact that terrorists are actively endeavoring to try to get access to in particular chemical, biological, and radiological weapons," said Alexander Downer. "The easiest of which would be radiological weapons. They could create what is sometimes called a dirty bomb very easily."

Mr. Downer said a dirty bomb, made up of conventional explosives with nuclear material, while not a nuclear bomb, would disperse radioactive material and cause widespread damage.

Mr. Downer said the international community should be limiting the number of countries that produce biological, nuclear, or chemical weapons.

The Australian foreign minister also urged the international community to see the importance of this issue.

"In Southeast Asia there may be a real sense of urgency, but when you get to the United Nations in New York it has to be said that there are quite a number of members there who don't see the urgency," he said.

Mr. Downer says countries need to improve security measures for radioactive and other hazardous materials and work together to improve global security.

Australia has worked closely with Indonesia over the past three years in fighting regional terrorism. Dozens of Australians were killed in two bombing attacks on the Indonesian island of Bali, which were carried out by members of the Jemaah Islamiyah group.

The Australian government also has been a major contributor to recovery efforts for Indonesia's Aceh province, which was hit by a devastating tsunami and earthquake a year ago. Mr. Downer is expected to visit Aceh Thursday to inspect reconstruction projects.