US calls for Iran sanctions over nuclear bomb fears

Iran defied the West today by starting enriching uranium to a higher level amid fears that it will be used for nuclear weapons.

State TV said the process began in the presence of inspectors from the UN nuclear watchdog agency.

Britain warned Tehran against the move and US Defence Secretary Robert Gates called for the United Nations to slap new sanctions on Iran in "weeks, not months".

America and France said Iran's action left no choice but to push harder for a fourth set of sanctions to punish Iran's nuclear defiance. Russia, which has close ties to Iran, appeared to edge closer to Washington's position, saying the new enrichment plans show the suspicions about Iran's intentions are well-founded.

Uranium has to be enriched to feed nuclear power plants and Iran says it needs the 20 per cent enriched fuel for a research reactor producing medical isotopes.