She flew in via Malta as Libya's new rulers try to crush the last pockets of resistance by fighters loyal to Gaddafi in his hometown of Sirte.
"This is Libya's moment. This is Libya's victory. The future belongs to you," she said, eight months after Libyans rose up against the four-decade rule of Gaddafi, sparking a conflict that has killed thousands.
Addressing National Transition Council chairman Mustafa Abdel Jalil and interim premier Mahmud Jibril, she said: "In crowded squares and mountain passes, you stood up against a dictator's aggression and claimed the rights and dignity of a free people ...