The UN's World Food Programme (WFP) said Wednesday it had begun delivering food to help more than 1.1 million Zambians hit by flash floods.
Luapula and Eastern provinces were swamped by floods that struck after the November-April rainy season.
"The COVID-19 pandemic hit Zambia as people affected by drought and flash floods were just starting to recover and rebuild their livelihoods," said Jennifer Bitonde, WFP representative in Zambia.
"This risks undermining resilience gains and further aggravating food insecurity of the most vulnerable," she said.
The landlocked southern African nation has so far recorded 832 cases of coronavirus, including seven deaths.
Zambia already had some 2.3 million people facing food shortages after last year's drought -- the worst in 35 years.
The WFP, working with the government, is delivering relief food to some 260,000 people in 32 flood-affected districts in central, northern and eastern parts of the country.