The United Nations emergency relief coordinator Valerie Amos has arrived in Syria at the start of a three-day regional trip to discuss humanitarian aid for Syrian civilians trapped or displaced by the fighting.
She is scheduled to meet Syrian authorities including deputy foreign minister Faisal Mekdad, as well as officials from the Syrian Arab Red Crescent.
They will discuss ways of increasing emergency aid to civilians, but diplomats say fighting must ebb before there is any real hope of gaining access to hot spots.
The humanitarian situation in Syria has worsened in recent weeks as fighting spread to Damascus and Aleppo.
Two million people are now estimated to have been affected by the crisis and 1.5 million have been internally displaced, according to the world body.
Meanwhile, the Sryrian president's special envoy is in China for talks with the foreign minister, as Syria attempts to bolster its diplomatic support.
Beijing is also reported to be considering an invitation to members of the Syrian opposition.