The head of the UN atomic watchdog warned yesterday that the world's growing appetite for nuclear energy could lead to dangers associated with unsafe technology and weapons proliferation.

International Atomic Energy Agency chief Mohamed ElBaradei said more than 60 countries were considering going nuclear amid an energy crunch and global warming concerns, adding to the 30 countries with existing programmes.

"(But) in some countries we see a troubling combination of old reactors, operations that are poorly managed or underfunded and weak regulations," Mr ElBaradei said in opening remarks to a nuclear power conference in Beijing.

"This needs to be addressed immediately," he added, calling for a greater international drive to ensure the safety of nuclear plants and security of fissile material.

He said there was a risk that countries which acquire nuclear energy technology may seek to develop atomic weapons.

"These countries may have no intention of ever making nuclear weapons but that can change quickly if their perceptions of risk to national security change," he said.

"And security perceptions, as we know, can change very rapidly."

Such concerns have been highlighted in recent years by international efforts to stop North Korea and Iran from allegedly trying to turn nuclear energy systems into weapons programmes.

Mr ElBaradei said growing energy demand and concerns about oil supplies and greenhouse gas emissions had triggered renewed interest in nuclear power.

He said 436 nuclear power reactors were in operation in 30 countries, providing about 14 per cent of global electricity supplies. But many more countries are also looking at the nuclear option, said Mr ElBaradei, adding that last year construction started on 10 new reactors worldwide, the highest since the 1986 nuclear disaster at Chernobyl.