"I therefore urge all donors and supporters to ensure that this flash appeal for Kyrgyzstan receives a generous and rapid response."
Low on supplies
Ban Ki-moon, the UN secretary-general, has said there are shortages of food, water and electricity in the violence-hit areas.
"Hospitals and other institutions are running low on medical supplies," he said.
An aid appeal for neighbouring Uzbekistan, where about 100,000 refugees have taken shelter, would be launched next week, Ban said.
His comments came amid reports that Kyrgyzstan troops are heading towards an Uzbek barricade in the southern city of Osh.
Al Jazeera's Robin Forestier-Walker, reporting from the capital, Bishkek, said the Kyrgyz troops are believed to be trying to get access to a fuel depot situated inside a neighbourhood in Osh.
"The depot was seized control of by ethnic Uzbek members of the neighbourhood," he said.
"They were trying to use that as a bargaining chip to ensure their safety.
"Because everywhere you go in Osh, the Uzbeks that you speak to believe that they are under attack and need to defend themselves from marauding gangs that have been causing such violence and devastation."
'Outside elements' blamed
For his part, Islam Karimov, Uzbekistan's president, accused "outside" elements of instigating the violence, saying neither ethnic Uzbeks nor Kyrgyz were responsible for starting it.
"Neither Uzbeks nor Kyrgyz are to blame for this," he was quoted as saying by the official Uza news agency on Saturday.
"These disruptive actions were organised and managed from outside.
"Forces that organised this subversive act tried to drag Uzbekistan into this standoff."
Kyrgyzstan's interim leadership has blamed Kurmanbek Bakiyev, the country's deposed president, of masterminding the violence.
Hillary Clinton, the US secretary of state, echoed those allegations, saying Bakiyev may be to blame.
"Certainly, the ouster of President Bakiyev some months ago left behind those who were still his loyalists and very much against the provisional government," she said in remarks posted on the state department website on Saturday.
"There certainly have been allegations of instigation that have to be taken seriously."
Bakiyev, now in exile in Belarus, has strongly denied any involvement in the events.
Clinton's statement came as Robert Blake, the US envoy to the region, visited Bishkek on Saturday for meetings with Kyrgyz interim government officials.
Blake, who visited a refugee camp near the Kyrgyz border a day earlier, urged Kyrgyzstan to create conditions for a safe return of the hundreds of thousands of refugees uprooted in the violence.
"It is important for the provisional government to establish the atmosphere of trust and security so the refugees in Uzbekistan and the internally displaced persons in Kyrgyzstan can feel confident that they can return to their homes and live in safety and harmony with their Kyrgyz neighbours," he said after talks with Roza Otunbayeva, the Kyrgyz interim leader.