As international talks in search of a cease-fire and regime change in Syria get under way in Switzerland, there is a humanitarian disaster unfolding that must take top priority.

Photos of the corpses of more than 11,000 people reportedly starved, tortured and executed in jails controlled by President Bashar Assad have been smuggled out of Syria by a police photographer. And fighting in the civil war has trapped tens of thousands of civilians without food, water and medicine now that Assad has embraced starvation as a weapon of war.

Achieving the ultimate goal of the United Nations diplomatic summit in Geneva-easing Assad from power-is a long shot. So as direct talks begin, the United States and its allies should demand a verifiable end to the systematic killing and press the Assad regime for a show of good faith: an agreement to allow convoys carrying humanitarian aid to reach suffering civilians.

About 250,000 civilians are isolated in rebel-held areas besieged by government forces, out of reach of aid deliveries. Millions more are in areas that are barely accessible. Aid workers have had little success negotiating access to the sick and starving in a country where about 9 million people-nearly half the population-have been driven from their homes.

Now that both sides in the conflict have joined the United States and others in negotiations, the immediate priority must be ending the atrocities.

Editorial, Pages 16 on 01/25/2014