President Barack Obama, center, walks up to the podium with former Presidents Bill Clinton, left, and George W. Bush, right, Saturday in the Rose Garden at the White House in Washington. Obama asked the former presidents to help with U.S. relief efforts in Haiti after the earthquake.

Washington ? President Barack Obama tapped former presidents George W. Bush and Bill Clinton on Saturday to head a major fundraising effort to underwrite Haiti’s long-term recovery, even as concerns grew about delivering life-saving aid to earthquake victims.

“Just send your cash,” Bush said, discouraging Americans from contributing blankets, water or similar items. The former president, making his first visit to the White House since leaving office a year ago, appeared with Clinton and Obama in the Rose Garden.

The three men said a Web site, clintonbushhaitifund.org, has been established to accept donations for the relief and reconstruction effort.

“There are going to be some tough days ahead,” Obama said. “People are still trying to figure out how to organize themselves. There’s going to be fear, anxiety, a sense of desperation in some cases.” He tried to reassure Haitians that “there is going to be sustained help on the way.”

Obama has mounted a major effort to help Haiti recover from the earthquake, which may have killed as many as 50,000 people and devastated the capital, Port-au-Prince.

Responding to the vast humanitarian need also boosts Obama’s effort to repair and reshape the United States’ image overseas.

Obama dispatched Secretary of State Hillary Clinton on Saturday to Haiti, where she was to meet Haitian President Rene Preval.

White House aides rejected suggestions that the trip was little more than a photo op that could interfere with relief efforts. The secretary of state traveled to Haiti from Puerto Rico aboard an aircraft already scheduled to carry supplies to U.S. embassy personnel, and would depart on a plane scheduled to evacuate about 50 U.S. citizens, they said.

In tapping Bush and Bill Clinton, Obama is following a model established by his predecessor, who asked former presidents Clinton and George H.W. Bush to lead a similar effort after the 2004 tsunami in southeast Asia.

Obama, with Bush standing to his left and Clinton to his right, praised Bush’s response to the tsunami and his administration’s efforts to combat HIV in Africa. But he pointedly did not mention the Bush administration’s handling of Hurricane Katrina, widely seen as botched.