U.N. Secretary-General Ban Ki-moon on Tuesday criticized the leaders of the world's wealthiest countries for failing to attend a pivotal humanitarian summit in Turkey which culminated with a long list of commitments and question marks over their implementation.

At the closing of the World Humanitarian Summit in Istanbul, the first of its kind, Ban said it was "disappointing that some world leaders" couldn't attend, singling out the Group of 7 countries -- Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States.

Only German Chancellor Angela Merkel attended the summit.

In an apparent reference to Russia, Ban also criticized members of the U.N. Security Council who have prevented progress "not only in critical issues of war and peace, but even on humanitarian affairs," stressing that the absence of these leaders didn't "provide an excuse for inaction."

The summit, which aimed to boost humanitarian responses to global crisis, drew the participation of 10,000 participants including 65 heads of states. President Barack Obama and Russian President Vladimir Putin, whose nations are striving to broker peace in Syria, were no shows.

Despite the absence of global heavyweights, Ban was encouraged by the results of the conference saying that more than 1,500 commitments were made by 400 government representatives, humanitarian organizations and other groups in line with the conference's priorities.

Top U.N. officials used the second day of the summit to call for greater preparedness for emergencies and increased protection for the most vulnerable. They unveiled a new "Global Preparedness" partnership so that 20 countries could be ready to face future risks, primarily caused by climate change, by 2020.

Stephen O'Brien, U.N. Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, said "very little at the moment goes to preparedness" when it comes to mitigating the risks of natural disasters or meteorological phenomena like El Nino.

Izumi Nakamitsu, director of the Crisis Response Unit of the U.N. Development Program (UNDP), said more steps need to be taken to "reduce the impact" of natural disasters. "We need to reach the most vulnerable, the most affected people first and very often these are women and children," she told The Associated Press.

"Women and girls are 14 times more likely to die of a natural disaster than men and boys," Jordanian Princess Sarah Zeid told journalists. "Conflict, contagion and climate are creating an unprecedented need. In all these settings, it is women and girls who are hit first, hit hardest, hit longest."

Upholding international humanitarian law, ensuring a seamless response between emergency relief and development, mobilizing more resources with greater efficiency to those in need and to local humanitarian actors, were other salient themes of the two-day gathering.

"The summit highlighted major gaps in the way the international community approaches crises," said Elhadj As Sy, secretary-general of the International Federation of the Red Cross and Red Crescent Societies.

While galvanizing strong participation, the summit has also come under sharp criticism -- particularly from rights groups who questioned the record of host country Turkey -- and many parties from the humanitarian and development communities concerned by the non-binding nature of the commitments made.

Sara Pantuliano, managing director at the Overseas Development Institute called it a "missed opportunity" saying the commitments that came out of it "fell short in substance and ambition."