Former US presidents Bill Clinton and George Bush Snr have ended their tour of tsunami-hit nations by visiting Sri Lanka and the Maldives.
President Clinton was moved by children's art showing the tsunami
Their fact-finding tour of areas struck by December's disaster also took them to Thailand and Aceh in Indonesia.
On Monday they visited Sri Lankan children who survived the tsunami and were briefed on reconstruction projects in the Maldives.
They said $11.5bn (£6.06bn) would be needed across the Indian Ocean.
The two men were asked by the White House to lead fund-raising efforts.
Mr Clinton said US President George W Bush had "made it clear that the US will do at least its fair share or more in the long run. We are committed to it".
In Sri Lanka, Mr Bush and Mr Clinton visited children at trauma counselling centres in Matara 160km (100 miles) south of Colombo.
Some of the children handed them drawings of their memories of the devastation.
Correspondents say both men were moved by the scale of the destruction, vividly portrayed in the crayon drawings.
"There's a lot of emotional damage here, not visible to the eye, and that is most pronounced in these children," Mr Clinton said.
Mr Bush said: "The children told me that they have snapped back and are not living in fear any more. That is the best aspect of being children."
The two former leaders did not visit areas in the north and east held by the Tamil Tiger rebels.
But Mr Clinton said he believed the rebels and the government could work together on reconstruction and help resolve the long-running dispute.
"It is my experience whether it is in the Middle East or Northern Ireland, when people are working together on specific projects a lot of differences can be resolved," he said.
Mr Bush and Mr Clinton held a private meeting with Sri Lankan President Chandrika Kumaratunga to discuss relief operations and long-term aid.
Bush and Clinton hope to help raise more money for reconstruction
So far the US government has given just over $60m to the tsunami relief effort in Sri Lanka, with one in three families in the US making a contribution.
Later on Monday the former presidents were welcomed at Male airport by the president of the Maldives, Maumoon Abdul Gayoom.
Mr Bush said he wanted to tell tourists that despite losing 62% of its gross domestic product because of the tsunami, the Maldives was "up and running" for business.
Earlier in the trip, Mr Bush and Mr Clinton went to Aceh province in Indonesia. They visited some of the refugee camps where tens of thousands of survivors are living.
They spent most of their time in the village of Lampuuk, which was flattened by the tsunami.
"I've never seen anything like this in my entire life," Mr Bush said.
The two men began their tour in Thailand on Saturday, where they visited tsunami-hit villages.