Australia's government says it need a way to protect its shores from ballistic missiles, even though at the moment the remote continent faces no threat from long-range weapons.

So Australian Defense Minister Robert Hill and Defense Secretary Donald Rumsfeld signed a pact Wednesday in Washington to develop and test missile defense systems, as well as establish joint training centers.

Mr. Hill says his government is committed to this ambitious project. "We have a responsibility to address not only the threats of today but the threats that we might face in the future," he says.

Australia joins a long list of countries, including South Korea, Japan, Britain, and Israel, which are working with the United States on its missile shield.

Development is in its early stages. Eventually the program aims to have the ability to track and destroy incoming ballistic missiles through advanced radar systems.

It is expected to cost tens of billions of dollars during the next five years.

The Pentagon plans to develop sea-based interceptors, fit lasers to planes, and to explore the use of firing rockets from space. Part of the missile screen is expected to be deployed later this year in Alaska. There is also a proposal to equip a new Australian destroyer with missile-defense technology.

Defense analysts say the joint project is aimed at the danger posed by North Korea - which is developing nuclear weapons and long-range missiles to deliver them.