"UNHCR plans to begin a massive airlift this weekend to bring tents and other aid supplies," said Adrian Edwards, spokesman for the UN High Commissioner for Refugees.

The first flight would arrive Sunday in Nairobi with about 100 tonnes of tents while at least six other planeloads are to follow over the next two weeks to bring another 600 tonnes of tents to the world's largest refugee camp.

Dadaab, located at the border with Somalia, was built for 90,000 people. But it is now home to nearly 440,000, including 59,000 who are living on the outskirts of the camp.

With the worst drought in 60 years hitting the Horn of Africa, the flow of Somali refugees arriving at the camp has increased over recent months, putting resources at the camp under severe strain.

On Thursday, Kenyan Prime Minister Raila Odinga pledged to open an extension at Dadaab to ease the severe overcrowding.

"We certainly can see the crisis level and it is important that the camps be opened," he said in Dadaab.

"Let the UNHCR work with the government on modalities of opening up the new camps," he added.

Edwards welcomed the announcement, saying that the UN agency's chief Antonio Guterres has written to Kenya's president and Odinga to applaud the decision as well as pledge UNHCR's full support.

Some 60,000 new arrivals have been recorded at Dadaab since the beginning of the year, according to the UNHCR.

Copyright AFP (Agence France-Presse), 2011