UN emergency aid chief Valerie Amos arrived in Damascus, the Syrian capital, Sunday for talks on the country's humanitarian situation amid an increase in the number of Syrians forced to take refuge in neighbouring countries due to the violence.
The UN envoy is expected during her two-day visit to meet with Syrian officials at the Foreign Ministry.
Amos' visit is the third to Syria since an uprising against President Bashar al-Assad's rule started in March 2011.
The UN has recently said that about 4 million Syrians are in urgent need of humanitarian assistance; at least 2 million of them were internally displaced.
Kuwait is to host a conference of donors for Syria on Wednesday.
In Syria, fierce fighting was ongoing between government troops and rebels on the outskirts of Damascus, reported activists.
Al-Assad's troops have recently stepped up a campaign directed at Dayara, a rebel stronghold south-west of Damascus located near a key military base.
State media reported that government troops were hunting "armed terrorist groups" - a term used to refer to rebel fighters - and accused the insurgents of killing civilians and destroying
infrastructure facilities.
Fighting was also reported near a train terminal in the rebellious area of al-Qadam, south of Damascus.
The violence prompted the closure of a key highway that passes through the area and links Damascus to the southern province of Daraa, the opposition Syrian Observatory for Human Rights said.
The Syrian army has been for weeks mounting ground and air assaults to drive insurgents from areas on outskirts of Damascus, More than 60,000 people have been killed in Syria's 22-month
conflict, according to UN estimates.