The UN's nuclear watchdog has declared North Korea to be in "complete defiance" of its international obligations, after Pyongyang ordered the expulsion of nuclear observers. Mohamed El Baradei, the head of the International Atomic Energy Agency (IAEA), told the BBC he was making arrangements for the two inspectors to leave by Tuesday. North Korea is in the midst of an escalating dispute with the United States, sparked by its alleged admission that it was resuming a nuclear programme, and Washington's retaliatory fuel sanctions. On Friday, tensions were further exacerbated when Pyongyang sent a letter to the IAEA demanding the withdrawal of observers, and announced it was reopening a nuclear reprocessing plant.