Secretary of State Hillary Rodham Clinton has canceled a trip to London and Turkey for international conferences on cyber security and Afghanistan because of her mother's illness.

Clinton had been scheduled to depart Washington late Monday but decided against the trip when her mother, 92-year-old Dorothy Rodham, became ill.

A State Department official says Clinton will remain in Washington. The nature of her mother's illness was not released.

Wednesday's conference in Istanbul is focused on creating a regional strategy for improving security and economic development in Afghanistan.