The largest aid convoy since the Syrian conflict started more than five years back entered the besieged rebel-held town of al-Rastan on Thursday, the Red Cross said.
Sixty-five trucks carrying food, medical supplies and other vital aid had reached al-Rastan in central Syria's Homs province, the International Committee of the Red Cross (ICRC) said.
The supplies were provided by the United Nations, ICRC and the Syrian Red Crescent to the town where 120,000 people are believed to be living.
"You feel the sense of urgency here. Rastan is one of the besieged areas that has not been accessed for a very very long time with humanitarian supplies," Pawel Krzysiek of ICRC said.
Specialized teams would conduct assessments of the town's health and water infrastructure, waste management mechanisms and nutritional situation, ICRC said in a statement.
Al-Rastan has been out of the control of Syrian government forces since 2012. It has witnessed heavy fighting in the past several years and even a recent respite in the clashes had not allowed for aid to reach the town.
The UN and aid groups have been using a cessation of hostilities agreement, which went into effect on February 27, to bring aid to besieged civilians.
On Wednesday, the UN said it was evacuating some 500 people from four areas under siege.
Since the February ceasefire, humanitarian deliveries have reached 12 of 18 areas besieged by government forces and rebels, UN special envoy for Syria, Staffan de Mistura, said Thursday.
"We have reached so far 560,000 people" there, he said.
De Mistura told reporters in Geneva that "modest but real progress" has been made in delivering relief supplies.
The truce brokered by Russia and the United States excludes the Islamic State terrorist militia and al-Qaeda's Syria branch, al-Nusra Front.