The Red Cross has warned that the humanitarian situation in Buchanan, Liberia's second port city, is increasingly desperate.
U.S. and West African officials are increasing pressure on Liberian rebels to open Monrovia's vital port and allow food supplies and aid to flow to famished refugees and residents in the capital.
But the rebels said only their top leadership could decide whether to allow Nigerian peacekeepers to deploy.
"At this point it will only be by force that they take this port," said rebel official Sekou Fofana of Liberians United for Reconciliation and Democracy (LURD) in Monrovia.
Still uncertain of President Charles Taylor's promise to step down on Monday and leave his ruined country, rebels are reluctant to leave ground they won in weeks of vicious street battles that left at least 2,000 people dead.
Guns have fallen silent in Monrovia since some 800 regional peacekeepers flew in, but that has made the daily struggle for survival only a little easier for hundreds of thousands of people scrabbling for whatever food they can find.
"We are very concerned about the reopening of the port," said Dominique Liengme, head of the International Committee of the Red Cross office. She said that as well as the food shortage, fuel stocks were also running low.
"If you don't have fuel you can't do anything. We need fuel to work, to run our generators for the hospital, for the offices," she said.
A team of U.S. officials and West African peacekeepers returned to inspect the port on Saturday after a visit on Friday, but the rebels said only their leader Sekou Conneh could decide when they would pull out.
Conneh was expected in main rebel backer Guinea following a trip to Europe.
Reuters