President Bush will leave Washington Friday to begin a five-nation tour of Africa.

On Thursday, Mr. Bush said he might delay his departure as he pressured Congress to renew an expiring domestic surveillance program.

But the White House said Friday the president and Mrs. Bush will leave Washington late in the afternoon and arrive in Benin on Saturday.Mr. Bush is scheduled to make stops in Benin, Tanzania, Rwanda, Ghana and Liberia during his week-long trip.

In a speech Thursday at Washington's National Museum of African Art, Mr. Bush described Africa as having enormous potential. He said his trip will show how compassionate Americans have been in providing money to fight AIDS and other deadly diseases.

Mr. Bush has proposed spending $30 billion over five years to combat the HIV/AIDS epidemic in Africa.

He also said in his speech that the U.S. will use its diplomatic resources to urge faster deployment of a United Nations-African Union peacekeeping force in Sudan's Darfur region.

In a later meeting with reporters, Mr. Bush denounced Zimbabwe's President Robert Mugabe as a "discredited dictator" who has ruined his country.

The U.S. president said he is disappointed that South African mediation has failed to ease Zimbabwe's political divisions. Mr. Bush said he was hoping that the South African government would have been more pro-active in trying to help the people of Zimbabwe.

South African President Thabo Mbeki has been mediating talks between Zimbabwean President Robert Mugabe's government and the opposition. Throughout the process, Mr. Mbeki has refused to speak strongly against Mr. Mugabe, who will seek a sixth term as president in March.