President Hakainde Hichilema appealed for help in a televised address, saying about half of the southern African nation's 20 million people have been adversely impacted by the prolonged dry spell induced by the El Nino weather phenomenon.
"Zambia has experienced extremely low rainfall this year, culminating in the worst drought the country has experienced since records began," he said.
The lack of rain has devastated the agricultural sector, affecting crops and pastures, Hichilema said.
More than six million people are in need of urgent humanitarian assistance.
But Zambia, which declared drought a national disaster in February, only has about $51 million of the $940 million it needs to deal with the crisis, he added.
"With a heavy heart, on behalf of our government and the people of Zambia, we hereby appeal to the international community, our partners within the country, the private sector, the church and civil society organizations, to support our plan financially and materially in mitigating the devastating effects of the drought," he said.
The naturally occurring El Nino climate pattern, which emerged in mid-2023, usually increases global temperatures for one year afterwards.
It is currently wreaking havoc across southern Africa, where Zimbabwe and Malawi have also declared a national disaster and asked for international support due to the lack of rain.