How Much Will Obama's Africa Trip Cost? The White House Isn't Exactly Sure

President Obama is about to head off to Africa for a weeklong trip with his family, where he will visit South Africa, Senegal and Tanzania -- but the White House isn't sure how much it's going to cost.

"We don't have the exact figure on costs -- frankly we don't own or control those numbers," Ben Rhodes, deputy national security advisor for strategic communications, told Yahoo News.

"The security requirements, which make up the bulk of the cost, are determined by the Secret Service, and they don't publicly release the breakdown of the costs for these types of trips."

Rhodes told Yahoo News that this isn't an unusual situation, as the Secret Service and White House military office typically set security costs for these kinds of trips.

The first family's visit to sub-Saharan Africa could cost the government between $60 million and $100 million, an anonymous source familiar with the trip told the Washington Post, based on the costs of similar presidential trips.

The Post sketched out some of the security resources those funds will be going toward, citing an internal Secret Service planning document obtained by the newspaper:

Hundreds of U.S. Secret Service agents will be dispatched to secure facilities in Senegal, South Africa and Tanzania. A Navy aircraft carrier or amphibious ship, with a fully staffed medical trauma center, will be stationed offshore in case of an emergency.

Military cargo planes will airlift in 56 support vehicles, including 14 limousines and three trucks loaded with sheets of bulletproof glass to cover the windows of the hotels where the first family will stay. Fighter jets will fly in shifts, giving 24-hour coverage over the president’s airspace, so they can intervene quickly if an errant plane gets too close.

Similar trips made by past presidents have also been costly. President Clinton's 1998 trip to six African countries cost the federal government an estimated $42.8 million, according to a Government Accountability Office report. That sum does not include Secret Service costs, the report notes, which are classified.