Two UN vessels arrived carrying food and other essential items while a plane landed in Monrovia's airport with supplies donated by Washington.
"This is the very first load of food," said an immensely relieved UN official.
A third ship laden with aid for the war-torn country sailed off from neighbouring Sierra Leone.
Justin Bagirishya, the director of World Food Programme for Liberia said his agency aimed to distribute food aid to more than 500,000 people.
Two UN vessels arrived carrying food and other essential items while a plane landed in Monrovia's airport with supplies donated by Washington
The arrival of the first consignment of supplies raised hopes of ending Monrovia's ordeal, where some 450,000 displaced people are living amid acute shortages of food, water and medicines.
Meanwhile, UN Secretary General Kofi Annan's special representative in Liberia said he would recommend the lifting of sanctions imposed on the government of president Charles Taylor, who stepped down and went into exile earlier this week.
"I will try to go back to the UN Security Council and get them lifted as quickly as possible," the representative Jacques Klein said.
The sanctions, that included an arms embargo and a ban on trade in rough diamonds, were imposed in 2001 to force abetting rebels in neighbouring Sierra Leone.