UNITED NATIONS — The U.N. peacekeeping chief says approximately 100,000 people have fled their homes because of an upsurge of violence in Sudan's Darfur region in the last six weeks.

Herve Ladsous said this adds to the nearly 2 million people displaced by the Darfur conflict, including 400,000 last year.

Ladsous told reporters that he presented the U.N. Security Council with a proposal Wednesday to improve the performance of the joint U.N.-African Union peacekeeping force in Darfur, whose primary role is protecting civilians.

U.S. Ambassador Samantha Power urged the peacekeepers to be more "aggressive and steadfast" in protecting civilians and facilitating the delivery of humanitarian aid.

Darfur has been gripped by bloodshed since 2003 when rebels took up arms against the government in Khartoum, accusing it of discrimination and neglect.