Jordan-Syria border
Jordan-Syria borderReuters

UN agencies announced Thursday the first delivery since June of desperately-needed food and hygiene supplies to tens of thousands of Syrians trapped on the border with Jordan.

The announcement came in a joint statement by the heads of the World Food Programme, the United Nations High Commissioner for Refugees, the children's agency UNICEF and the International Organization for Migration.

Jordan closed its border with Syria in June after a suicide bombing claimed by the Islamic State jihadist group killed seven soldiers.

The attack took place near a makeshift desert camp and aid groups have since been unable to deliver supplies to tens of thousands of Syrian refugees stranded at the border.

The heads of the four UN agencies announced the "successful completion (on Thursday) of a relief operation to provide more than 75,000 people with food and humanitarian items".

"Unable either to cross the border or turn back, the situation facing these women, men and children has grown more dire by the day," they said.

"Sheltering in makeshift tents in harsh desert conditions with temperatures of up to 50 degrees Celsius (120 degrees Fahrenheit) and sudden sand storms, they are without sufficient food and have barely enough water to survive," the statement added.

The UN aid agency heads warned that health care was "urgently" needed, particularly for pregnant women, children and other vulnerable groups such as the elderly and the sick trapped along the border.

"We look forward to further efforts to reach people at the berm with humanitarian assistance in time to save their lives," they said, thanking the Jordanian government for its cooperation.

Jordan declared the border area a "military zone" after the June attack, blocking access to Syrian refugees and sparking fears over their fate.

Several international aid and rights groups have since urged Jordan to revoke its decision and keep its borders open to refugees fleeing Syria's five-year war.

Jordan already hosts hundreds of thousands of Syrian refugees.

It had agreed in July to a one-off aid delivery for those trapped on its border after an appeal by the United Nations.