The International Atomic Energy Agency says U.S. Energy Secretary Spencer Abraham will visit its Vienna headquarters later this month to launch a new initiative on nuclear non-proliferation.

IAEA spokeswoman Melissa Fleming confirmed top-level talks are planned on a global clean-up of highly enriched uranium from civilian reactors.

"There are major initiatives by the U.S., and Secretary of Energy Abraham is coming to Vienna the week after next to announce new U.S. measures to attack that problem," she said.

The United States is already financing a program to send weapons-grade uranium from Eastern Europe and former Soviet states back to Russia.

Experts fear many of the reactors are run-down and poorly guarded, making them a possible target for terrorists.

At the end of last year, a U.S.-led team evacuated highly enriched uranium from an inactive research reactor in Bulgaria, and flew it to Russia, where it was blended down as reactor fuel. Similar joint operations with the IAEA have taken weapons-grade uranium from reactors in Romania and Serbia.

Now, the United States is planning to have large quantities of highly enriched uranium in reactors in Ukraine and Belarus processed as well, and talks are under way with Uzbek authorities to take similar security measures at a reactor near the Afghan border.

Analysts at Harvard University say there are hundreds of reactors in the world with highly enriched uranium that could be used by terrorists to make a bomb. Secretary Abraham visited the IAEA headquarters last September, and warned then that nuclear material, if not properly guarded, could fall into the hands of terrorists.

The United States is engaged in a program to replace dangerous uranium in reactors it once supplied, and, so far, has retrieved about half of the material. The aim of the latest missions is to take out the weapons-grade uranium in reactors world-wide, and fly it back to the country of origin, either the United States or Russia, by the end of 2005.