A mural-style painting at the World Humanitarian Summit in Istanbul bears the message «One Humanity», May 24, 2016. TRF/Megan Rowling

ISTANBUL, (Thomson Reuters Foundation) – The World Humanitarian Summit has reinforced the urgent need for people hit by conflict and disasters to receive better help, but the first meeting of its kind may not trigger the changes necessary to fix their plight, aid officials and experts say.

Vital to any long-term success is a ramping up of efforts by world leaders to end the wars that are causing record numbers of people to be uprooted, they said.

Yet the absence of many of the most powerful heads of governments, including the leaders of the U.N. Security Council’s permanent members, disappointed aid officials at the summit in Istanbul this week.

As the two-day conference ended on Tuesday, outgoing U.N. Secretary-General Ban Ki-moon, who convened the summit, appealed to Britain, China, France, Russia and the United States to act.

«The absence of these leaders from this meeting does not provide an excuse for inaction,» Ban said. «They have a unique responsibility to pursue peace and stability, and to support the most vulnerable.»

The summit drew only 55 heads of state or government with German Chancellor Angela Merkel the only G7 leader present.

Pledges made at the summit include an education fund aimed at raising $3.8 billion for emergency schooling, and a «grand bargain» between major donors and agencies to administer aid more efficientl