UNITED NATIONS - The head of the United Nations office for humanitarian affairs will visit Syria starting Tuesday, partly to discuss how to improve access and delivery of aid to conflict-affected zones, the UN said on Monday.Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Mark Lowcock will be in the capital Damascus for most of his three-day mission and will also visit Homs, the UN said, in his first visit in this capacity.The most recent visit by a UN humanitarian chief was in December 2015."In Damascus, Mr. Lowcock is expected to meet Government officials, humanitarian agencies and partners, and other key stakeholders," the UN said in a statement."In Homs, he will meet with people who have suffered first hand from the effects of the crisis, and need life-saving assistance."UN agencies began on Monday delivering aid for the first time in six months to some 60,000 Syrian refugees stranded in a desolate area near where Syria's border meets the Jordanian and Iraqi frontiers, aid agencies and Jordanian officials said.The International Committee of the Red Cross said late last year it hoped to resume evacuations of critically ill people from Syria's biggest remaining siege in rebel-held eastern Ghouta.A Syrian "congress of national dialog" is scheduled to meet in the Russian city of Sochi this month. UN Syria envoy Staffan de Mistura has said this meeting should be assessed by its ability to support the UN-led Geneva talks on ending the war in Syria, which has been raging for nearly seven years.