Irish humanitarian aid agencies have expressed disappointment at a UN Security Council resolution to extend cross-border aid to Syria, via Turkey, for just six months.
Members had sought an extension for a full year, however, the Security Council bowed to the Russian demand of six months.
Russia is a strong ally of Syria and last week vetoed a proposal for a year extension.
The measure received support from 12 of the Security Council's 15 members, including Russia, China, and the grouping's 10 non-permanent members.
One ambassador said that the UN Security Council "could not let people die".
"Russia forced everyone's hand: either the system would be ended, or it was extended for six months," the ambassador said.
Four Irish aid agencies (Trocaire, Oxfam Ireland, GOAL and World Vision Ireland) say the fact the agreement was only to keep the border crossing open for six months makes it difficult to plan for the level of critical aid that is now required.
"This still means huge uncertainty for the 4.1 million people trapped in northwest Syria already living in appalling misery and dependent on food, medical care and shelter, delivered by way of the border crossing," the agencies said in a joint statement.
The aid agencies said they appreciated the diplomacy shown by the Irish Government to seek an extension of the border mechanism for a further 12 months, which would have provided a more stable solution.
"While we welcome the fact that for now vital humanitarian aid can still be delivered through the one remaining border crossing at Bab al-Hawa, a more long-term solution is required" the statement said.
UN Secretary General Antonio Guterres expressed similar concern, saying extending the aid - particularly for the people of Idlib in Syria's rebel-held northwest - "is a matter of life and death for many of them."
"We asked for a renewal of one year. The Security Council approved six months," he said. "But I strongly hope that after six months it will be renewed."
The system, in place since 2014 and which more two million people rely on for assistance, had expired on Sunday.
The agreement, introduced by Ireland and Norway, breaks an impasse that had threatened to derail the life-saving supplies.
The new Irish-Norwegian text provides for a renewal in January 2023 for another six months, subject to the adoption of a new resolution.
Both Ireland and Norway expressed relief that aid would continue to flow.
More than 4,600 aid trucks, carrying mostly food, have crossed Bab al-Hawa this year, helping some 2.4 million people, according to the UN's Office for the Coordination of Humanitarian Affairs.
Additional reporting by Eleanor Burnhill
