The UN and aid agencies are hoping to deliver food and medicine to some 3,000 civilians trapped in Homs, Syria.The aid convoys are due to enter on Saturday on the second day of a temporary ceasefire in Homs between government forces and rebels.
On Friday more than 80 people were evacuated from rebel-held areas which have been under siege for 18 months.
Many of the evacuees looked frail and exhausted – some said they had not eaten bread for five months.
Large areas of Homs – Syria’s third largest city dubbed “the capital of the revolution” against President Bashar al-Assad – have been reduced to rubble by fighting between rebels and government forces.
Many neighbourhoods lie in ruins and activists say people have survived on little more than olives for weeks.
The situation in besieged districts of the city since June 2012 was discussed during peace talks in Geneva a week ago, but the humanitarian aid deal was actually struck between the governor of Homs and the UN resident co-ordinator in Syria.
The Syrian government is making no connection between the Homs agreement and the peace talks, but it was first mooted by the mediator there, Lakhdar Brahimi, says the BBC’s Jim Muir in Beirut, Lebanon.
The agreement’s success so far has cautiously improved the diplomatic atmosphere, our correspondent adds.
Another round of talks is scheduled to begin on Monday and the Syrian government has confirmed it will attend.
Reports of how long this truce will be in force are confused, with Damascus ally Russia saying three days and activist groups saying four.
The UN’s humanitarian co-ordinator in Syria, Yacoub El Hillo, said UN teams “have pre-positioned food, medical and other basic supplies for immediate delivery… we hope to send this aid on Saturday morning”.
He said that achieving the evacuation of civilians and the delivery of food was a “milestone” for which all parties should be commended.
Our correspondent says officials regard this second phase of the relief operation as the most delicate step in the carefully planned set of arrangements, and there will be relief and growing confidence if it passes off smoothly.
The area is controlled by a variety of armed rebels that the regime calls “terrorists”, and in the past, it has been reluctant to see food and medicines fall into their hands.
The UN said 83 civilians – mostly elderly people, but also women, children and the severely ill – were evacuated on Friday, after the government and rebel fighters agreed to observe a “humanitarian pause” in fighting.
In New York, UN spokesman Farhan Haq said that while there were isolated reports of gunfire, the operation had gone smoothly and the hope now was that more vulnerable civilians would be evacuated and more aid delivered over the next few days.
Red Crescent volunteers were seen helping a frail-looking old men wrapped in blankets on to a bus, while a woman on a stretcher awaited her turn.
BBC Arabic’s Assaf Abboud in Homs says the evacuated people were given meals and drinks and were taken for medical checks.
They told journalists that there were more people trapped in the city who wanted to leave.
An amateur video filmed by activists showed one man smiling and embracing his son as they were reunited after 18 months.
The evacuations are expected to resume on Sunday, local cleric Abdul Hareth al-Khalidi told the AFP news agency.
Homs has been a key battleground in the uprising against President Assad.
The army launched a series of big attacks to recapture rebel areas in the Old City in the beginning of 2012, with almost daily bombardments killing thousands.
President Assad’s forces enforced a blockade in June 2012 after recapturing most of the city, driving the rebels into a small enclave in the city’s centre.