SAN FRANCISCO, June 18: The United States is lobbying its European allies and Japan to spend 10 billion dollars to prevent terrorists from gaining access to nuclear, chemical and biological materials dispersed across the former Soviet Union, it was reported here.

That amount, spread over the next decade, would roughly match what the United States is expected to spend on a wide range of safeguards, including better security at Russian weapons sites, disposal of weapons-grade nuclear material and destruction of stocks of chemical arms, the San Jose Mercury News said.

The nuclear attacks that worry experts are far more devastating than the “‘dirty bomb” at the heart of a plot that US authorities uncovered last month and publicized on June 10, the paper said.

A “dirty bomb” is a conventional bomb combined with radioactive waste and generally is far less deadly than other weapons of mass destruction.

The U.S. initiative is an attempt to transform what has been primarily an American preoccupation into a global priority. It will be on the agenda when President Bush meets the leaders of the G-8 in Alberta, Canada, on June 26-27.

So far, Bush’s plan for a cooperative global effort to deal with the threat that some of this material could fall into terrorists’ hands has been met with praise from Washington’s foreign partners — but no hard offers of cash, the paper said.

Worldwide stockpiles of separated plutonium and highly enriched uranium, the key ingredients of nuclear weapons, total nearly 500 tons and 1,870 tons, respectively, according to a report issued last month by experts at Harvard University.