The convoy of 78 trucks taking food, bedding and medicine to Syria's mainly Kurdish Hasakah province was seen as a test of the willingness of Syria's authorities and rebels to abide by a U.N. resolution urging them to let aid across front lines and borders by the most direct routes.
But no distribution lists have been made available for this or any other U.N. delivery since the resolution, aid workers in Gaziantep near the Turkish border say, hampering the efforts of a plethora of charities trying to co-ordinate a response to the world's biggest humanitarian crisis.
"We still don't know where it went and we're not comfortable with this. The U.N. is constrained by the (Syrian) regime," said a Turkish official, speaking under condition he not be identified as his government has not taken a public stance on the issue.
Syria's war has killed more than 150,000 people, with more than nine million in need of humanitarian assistance. Its complicated patchwork of fighting has made aid provision harder.
The United Nations estimates 3.5 million of the people in need of aid live in areas that are difficult or impossible to reach for humanitarian workers, including more than 240,000 people besieged by government or opposition forces.
The convoy, dispatched over a largely deserted frontier to a region controlled by forces loyal to President Bashar al-Assad, was meant to be a test case to show that the issue of access can be dealt with under the U.N. resolution. But there were doubts from the outset over whether assistance would reach those in rebel-held areas in need.
According to stipulations set by the Syrian government, the delivery was passed to Syrian partner agencies including the Syrian Arab Red Crescent.
Reuters asked the United Nations in Damascus for information on the final distribution of aid in Hasakah, but was told no one was available to speak. The Syrian Arab Red Crescent could not be reached for comment.
The U.N. resolution, adopted by the Security Council in February in a rare show of unanimity on Syria, sought to boost humanitarian access and threatened to take "further steps" if Syria's government and the rebels failed to comply.
But the lack of transparency around U.N. deliveries makes that hard to monitor, according to international non-government organizations (NGOs), which wrote to several U.N. Security Council members last month warning a lack of coordination meant assistance was not reaching priority areas.
"I can't know if it's done well or badly as the U.N. hasn't told us exactly who the aid has gone to," said the project manager of one Western NGO, declining to be identified for fear of jeopardizing already fragile relations with the world body.
"It's doubly damaging because there is no accountability, transparency or coordination and all the while Assad is claiming credit (for aid deliveries) and criminalizing anyone who is crossing the border in rebel-held areas."
"SCATTERED LIKE SEEDS"
The United Nations has delivered shipments of aid from within Syria to some rebel-held areas, including most recently in the northern districts of Aleppo and Idlib, but the Hasakah delivery is so far the world body's only attempt to reach rebel-held areas from across the Turkish border.
NGOs complain that despite multiple requests, the United Nations has so far failed to share its methodology in identifying those most in need and monitoring where its aid goes after delivery. Often it does not even disclose what its food aid includes.
That makes effective coordination among the dozens of Syrian and international agencies operating out of Turkey, most of them using the southern city of Gaziantep as a hub, unnecessarily complicated, they say.
"It starts with coordinated needs assessments, coordinating with donors and responding in a systematic way. We immediately monitor where the aid went," said Dominic Bowen, coordinator of the NGO Forum in Gaziantep, which represents international groups making cross-border aid deliveries.
"Failing to do so can result in duplication and massive market distortion," he told Reuters.
One European charity said it had to cancel an aid delivery to Idlib about a month ago, after being told a day in advance that the United Nations planned to serve those areas. U.N. officials did not reveal their specific distribution plan.
"The U.N. is not alone. They should be part of the group. We're all equal," said the project manager of the NGO, which delivers some 30 trucks of food baskets and bread to Idlib and Aleppo each month.
"Distribution is not just crossing the border and scattering aid like seeds," he said, also speaking on condition of anonymity to avoid antagonizing the United Nations.
The United Nations' Jordan-based regional Humanitarian Coordinator Nigel Fisher acknowledged the concerns.
"Obviously this is a critical issue. People on all sides recognize there are problems with developing an information sharing program," he said, recognizing that the majority of cross-border assistance was being delivered by NGOs and saying that efforts to improve coordination were underway.
"STEP IN THE RIGHT DIRECTION"
A meeting in Gaziantep at the end of last month brought together more than 100 aid workers from the United Nations and Syrian and international NGOs. Delegates said frustration that the world body had to seek approval from the Syrian government for its deliveries in spite of the February Security Council resolution was the "elephant in the room".
"The idea of cross border deliveries itself is not a mistake. But they need permission of the regime and it is not letting them deliver where the aid is most needed," said Yakzan Shishakly, director of Syrian NGO Maram Foundation.
He said Syrian NGOs needed the United Nations to help direct funding because donors trusted the world body.
Fisher, the Jordan-based U.N. humanitarian coordinator, said the United Nations was "very sympathetic" to NGO concerns over access to donor money.
Several NGOs also called on the United Nations to help overcome other barriers such as administrative hurdles by lobbying host nations including Turkey, which had to agree to the U.N. convoy crossing in March.
"Advocacy, opening up borders, overcoming challenges to humanitarian actors getting visas, generally helping us to deliver aid from Turkey which we have been doing for years - the (February) resolution gives them cover to do this," said the project manager of the Western NGO.