ABU DHABI: The president of the United Arab Emirates has canceled a meeting with US Secretary of State Hillary Clinton, a US official said Monday, following a report that he had broken his arm. The official did not give a reason for the cancellation. The UAE's state news agency said Sheikh Khalifa Bin Zayed Al-Nahayan “fractured his arm this morning while undertaking his daily exercise.” “Sheikh Khalifa will rest for several days,” it added without giving further details. Clinton arrived in Abu Dhabi Sunday at the start of a tour of Gulf countries. In August, the UAE said Khalifa, who was born in 1948, had received medical treatment for an undisclosed illness in Switzerland where he spent a month convalescing. Sheikh Khalifa is the ruler of the wealthy oil-exporting Gulf Arab emirate of Abu Dhabi and the president of the US-allied federation, the United Arab Emirates. Analysts and diplomats say Sheikh Khalifa has appeared frailer than normal in public appearances over the past two years. They say Abu Dhabi Crown Prince Mohammed Bin Zayed, who is expected to succeed Sheikh Khalifa as UAE leader, is running day to day affairs. The UAE groups Abu Dhabi and six other emirates, including the regional business hub and tourist magnet Dubai. Abu Dhabi is the seat of the federal union.