President Bush says that the most destabilizing thing that can happen in the Middle East and in the world is for Iran to develop a nuclear weapon.

During a joint news conference Wednesday in Kabul with Afghan President Hamid Karzai, Mr. Bush repeated Washington's position that Iran should not be allowed to develop nuclear arms.

In Japan Wednesday, Iranian Foreign Minister Manouchehr Mottaki said his country has accepted in principle a Russian proposal to enrich uranium for Iran's nuclear energy needs. But he said the period of time and the place for uranium enrichment must still be negotiated.

A high level Iranian delegation is in Moscow Wednesday for more negotiations on the nuclear issue.

Mottaki also said that Iran has nothing to hide about its nuclear activities.

The United States and European Union say Iran is pursuing nuclear weapons - a charge it denies.

Some information for this report was provided by AFP and AP.