LONDON (AFP) - Iran has carried out secret tests of ballistic missiles capable of delivering a nuclear payload in breach of UN resolutions, British Foreign Secretary William Hague said Wednesday. Hague's comments came a day after Iran's elite Revolutionary Guards said they had fired 14 missiles in an exercise, one of them a medium-range weapon capable of striking Israel or US targets in the Gulf. In a statement to lawmakers, Hague said: "Iran has also been carrying out covert ballistic missile tests and rocket launches, including testing missiles capable of delivering a nuclear payload in contravention of UN resolution 1929." He said Iran had also announced plans to triple its capacity to produce 20 percent enriched uranium, adding: "These are enrichment levels far greater than is needed for peaceful nuclear energy.