Oxfam's humanitarian campaign manager Camilla Jelbart Mosse said:
"Leaders at this G8 Summit have shown some unity by pledging their commitment to finding a political solution to the Syria crisis and making a strong call for greater humanitarian access to help the Syrian people.
But there is still a mountain to climb. The international community must not let this momentum slip, or undermine it - the people of Syria cannot be left to suffer as the world argues over a solution to the conflict.
"It is essential that a timetable for the Geneva peace conference is put in place immediately. Full participation at the peace talks is needed from all sides of the conflict, as well as non-military representatives including the refugee community and women's groups.
"We welcome the UK government's £175 million in new funding for Syria and its neighbours, doubling the UK's funding for the country. The G8 leaders must act quickly to deliver the money they have pledged to help the eight million Syrians in need of aid."