The besieged Syrian town of Madaya needs a constant supply of aid, not just a single delivery, Doctor Without Borders (MSF) said on Sunday.
As aid agencies wait to gain access to the rebel-held area, which has been besieged by government forces since July, the medical charity warned that residents were suffering from continuing starvation and shortages of medical supplies.
There were 150 people severely ill, 10 of them in a critical condition, in a local hospital supported by MSF, the organization's deputy medical director Tammam Aloudat told dpa.
"Ten [of the patients] will die if there is no medical treatment shortly," he said.
The International Committee of the Red Cross says it is hoping to deliver aid to Madaya and to two government-held villages besieged by rebels in northern Syria on Monday.
But Aloudat said that it will also be necessary to evacuate people from Madaya, where the hospital is treating people wounded by gunfire and landmines as they tried to escape the town.
A consistent supply of aid was also needed, Aloudat said: "A single [aid] drop will not solve the problem."
MSF says that 23 people have died of starvation in the Madaya hospital since the beginning of December.
Local activists say residents have been reduced to eating grass and leaves in order to survive, and the situation has worsened with winter snowfalls.
"We are helpless, we are waiting ... but people are dying and the more time, the more tragedies," Madaya activist Mazen Burhan told dpa via Skype.
Madaya is one of the last rebel-held areas between Damascus and the Lebanese border.