ISTANBUL (Reuters) - Turkish President Tayyip Erdogan and U.N. Secretary-General Ban Ki-moon said on Tuesday they were disappointed Chancellor Angela Merkel was the only G7 leader to attend a summit on how the world deals with humanitarian crises.

Turkish President Tayyip Erdogan (R) and U.N. Secretary-General Ban Ki-moon shake hands following the closing news conference during the World Humanitarian Summit in Istanbul, Turkey, May 24, 2016. REUTERS/Murad Sezer TPX IMAGES OF THE DAY

The meeting, which drew 55 heads of state and government, sounded a “wake-up call” about the scale of the problems. But many participants saw the event as a modest step that fell short of stirring political will for real change.

“It is a bit disappointing that some world leaders could not be here, especially those from the G7 countries,” Ban told a news conference at the end of the summit.

Disasters, both man-made and natural, mean that 130 million people need humanitarian aid, costing an annual $240 billion, a 12-fold increase since 2000 but still just 1 percent of global military spending, he said.

Summit host Turkey is at the forefront of efforts to control the flow of migrants from Syria and elsewhere to Europe, which has confronted the continent with its biggest refugee crisis since World War Two. Erdogan said he was “saddened” that the leaders of Canada, Japan, Britain, Italy, the United States and France failed to show up for the two-day event in Istanbul.

In what was seen as a diplomatic snub, Russia - one of five permanent members of the U.N. Security Council which can veto resolutions - also failed to send a high-level delegation.

Moscow was concerned about a plan to limit the veto powers of Security Council members in certain situations.

Ban said divisions among the permanent members of the Security Council have stymied efforts to end war and promote peace, as well addresses humanitarian issues.

In a paper ahead of the summit, Ban urged the permanent members to withhold their veto power on measures addressing mass atrocities, a step welcomed by Helen Clark, head of the United Nations Development Programme and a candidate to succeed Ban when his term expires at the end of this year.

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The U.N. “is not seen as able to cope with today’s conflicts,” she told Reuters. “By the time an issue has gotten to the Security Council, the world has already failed.”

‘OVERWHELMING’ CHALLENGES

“This one summit is not going to be able to galvanize a level of political will to deal with what we’re all facing, which is really overwhelming,” said Justin Forsyth, deputy executive director of the U.N. children’s agency UNICEF, saying the summit meant a “modest step forward.”

Participants pushed for more efforts at crisis prevention.

Nancy Lindborg, head of the U.S. Institute of Peace, said the U.N. lacks the tools to prevent and end conflict, describing “paralysis” on the Security Council.

“The summit is a giant wakeup call to the political leadership that, hey, the world is on fire. We can fix how we provide humanitarian assistance, but you need to muster the political will to end these terrible conflicts.”

The summit launched an education fund aimed at raising $4 billion for emergency schooling, and a “grand bargain” which commits major donors to more funding in return for aid groups being more transparent about how they spend the money.

Sixteen aid organizations, the European Commission and 17 countries endorsed the agreement, but Turkey, which Erdogan said was the world’s second-biggest donor, did not.

Salil Shetty, secretary general of rights group Amnesty International, said without any binding documents and only voluntary commitments, the summit in Istanbul was a staging post for a follow-up conference in September in New York when there need to be clear specific outcomes.

“This one is principles and broad statements, which is simply not good enough. People are suffering. We need action.”