Saleh, 69, arrived in the United States in January to receive treatment for wounds inflicted during an assassination attempt last year.

Saleh is a long-time US ally, but his 33-year rule of Yemen formally ended on Tuesday after an uncontested election. His deputy, Abd-Rabbu Mansour Hadi, is taking over as president.

Saleh is the fourth veteran Arab leader unseated by "Arab Spring" protests.