The WHO brought 35 ton of relief aid to Aleppo on Saturday as Ghebreyesus reached the city and visited some hospitalised people, shelters where displaced people are staying, and damaged areas.
His visit comes in the wake of the deadly earthquake that rocked Syria on Monday, killing 5,000 people in government and rebel-held areas, Xinhua news agency reported.
Speaking to reporters during his tour, the WHO Director-General said that easing the US sanctions on Syria within the next 180 days would give a window to bring more emergency supplies and support.
According to a UNHCR estimation, 5.3 million people in Syria might have been left homeless by the earthquake.