"The main challenge is the lack of humanitarian access," said Dentice.
But activists say the world body's reach in rebel-held areas is limited, given the government's control of humanitarian access.
Last year, since the main rainy season was very good, and a bumper harvest ensued, the effect of the lack of humanitarian access was not clear.
Cameron also called for a "political and diplomatic breakthrough on the problem of humanitarian access", calling for agreement on the need for "unfettered humanitarian access inside Syria".
The situation in Somalia is more acute because of the fighting between al-Shabab and other militias, the absence of effective government and lack of humanitarian access.
The episode highlights the politicisation of humanitarian access, once a key pillar of peace talks in Geneva under US, Russian and UN auspices.
Israel is still blocking the facilitation of humanitarian access and continuing to shoot on civilians here". Mr Abbas is also cautious about the word "massacre".
Senior officials on the Syrian opposition umbrella negotiating body have resigned over the lack of progress of the talks, breaches of the ceasefire and lack of humanitarian access.
The inability of the international community to deliver aid to southern Unity, an area the UN says faces catastrophic food shortages, highlights the broader challenges of humanitarian access in South Sudan, which was plunged into civil war two years ago.
Bettati, at Kouchner's instruction, drew up a statement laying out a right of "humanitarian access," read it out to the crowd and then passed it to Chirac, who vowed to take the text to the United Nations.
The establishment of safe havens and of humanitarian access corridors, policed and enforced by experienced UN forces, could provide essential security for many Syrians, and would help immeasurably to stem the flow of refugees.
