Bottlenecks and infrastructure damage have been holding up aid efforts in Haiti, where Tuesday’s earthquake has left as many as 45,000-50,000 dead.
There is little sign of aid supplies beyond the airport, and correspondents cite increasing anger among survivors.
Many are spending another day without food and shelter in the ruined capital.
The US defence secretary said the Haiti relief effort was the main US priority in the western hemisphere, as an aircraft carrier arrived off the coast.
On Friday, the UN said a total of about $270m (£165m) in international aid had been pledged so far for the relief effort.
It will launch an emergency appeal for $550m later on Friday, UN spokeswoman Corinne Momal-Vanian said.
News from: http://news.bbc.co.uk/1/hi/world/americas/8460574.stm