"We need much more such convoys", he wrote.
"First UN and Syrian Red Crescent inter-agency convoy this year crossed conflict lines to Nashabieh in Eastern Ghouta to deliver food, health and nutrition supplies for 7,200 people in the besieged enclave", the UN humanitarian affairs office said. "Fighting has to stop to deliver much-needed aid to all civilians in need", he said in a tweet.
The nine-truck shipment is the first to reach Eastern Ghouta this year, follows pressure from the United Nations and other major aid agencies on the Syrian government to allow the convoy through.
Last week was one of the bloodiest in the almost seven-year-old conflict as Syrian government forces, who are backed by Russian Federation and Iran, bombarded two of the last major rebel areas of Syria - Eastern Ghouta and the northwestern province of Idlib.
The relief items included some 1.8 million tonnes of medical supplies from the World Health Organization (WHO), its representative in Syria Elizabeth Hoff told Reuters.
Hoff said that there was no news regarding the more than 700 patients who await medical evacuation from Eastern Ghouta, for which the United Nations health agency has been seeking government approval for months.
The humanitarian situation in Syria has significantly deteriorated due to the ongoing civil war.
The UN Security Council is now considering a draft resolution demanding a 30-day ceasefire in Syria to allow for urgent deliveries of humanitarian aid.