The Covid-19 pandemic could almost double the number of people suffering acute hunger in the world, pushing it to more than a quarter of a billion by the end of 2020 according to the United Nations World Food Programme.
In South Sudan, 61% of the country's population is already in a state of food crisis, or worse.
"Nowhere else in the world has the level of food insecurity as South Sudan," says Matthew Hollingworth, the country's Director for the WFP.
"Last year, we had to feed five million people due to fighting and flooding. Already in 2020 we have had locusts invasions and now there is the Covid-19 pandemic which we predict could almost double the people in acute hunger by the end of 2020 across the world. The only way we can halt this trend is if generous funding for humanitarian crises like the one here in South Sudan continues."
#COVID19 : Preparation underway for routine cleaning & disinfecting of @WFP_UNHAS aircraft so we can still transport critical life-saving personnel & light cargo to various locations across #SouthSudan SAFELY! This happens before & after flights. pic.twitter.com/vB7FbbCSGZ— Matthew Hollingworth (@mfjhollingworth) April 22, 2020
However, the World Food Programme is worried that as revenues in donor countries dry up, this will have an impact on much needed foreign aid.
"Lockdowns and economic recession are expected to lead to a major loss of income among the working poor," says World Food Programme (WFP) Executive Director David Beasley.
"Overseas remittances will also drop sharply. This will hurt countries such as Haiti, Nepal, and Somalia just to name a couple. The loss of tourism receipts will damage countries such as Ethiopia, where it accounts for 47% of total exports. The collapsing oil prices in lower-income countries like South Sudan will have an impact significantly, where oil accounts for 98.8% of total exports."
Civil war broke out in South Sudan in 2013, less than two years after the country gained independence from Sudan following decades of war.
The conflict has killed an estimated 400,000 people and forced millions from their homes.
The World Food Programme is also active in Malawi where many crops and livelihoods were destroyed last year following Cyclone Idai.
One of the poorest countries in Africa, it has started to record its first cases of the new coronavirus, although a court last week temporarily blocked a government order imposing a lockdown there.
Health experts are urging lower income countries such as Malawi not to focus only on lockdowns but to urgently scale up their health systems.
"Like everywhere, flattening the curve is the idea but if your health system doesn't have any intensive care beds - or like Malawi, has got 25 beds for 17 million people - you can't flatten the curve to the extent that'll work," said Glen Hines, Save the Children’s Executive Director for global programmes.
She said her organisation is now working to provide solar powered concentrators in Malawi which has intermittent electricity, no domestic oxygen plant and often struggles to secure imports of medicines.
The United Nations and aid agencies have warned of a catastrophic outcome if Covid-19 were to spread through the acutely malnourished population in Yemen.
A five-year war there has destroyed the country's health system, leaving millions vulnerable.
It has reported just one laboratory-confirmed case of Covid-19 but has very little testing capacity, ventilators or protective clothing.
Around 80% of the population or 24 million people there already require humanitarian aid.
The United Nations's food agency has warned of the potential for widespread famines 'of biblical proportions' due to the Covid-19 crisis | Read more: https://t.co/CiYZ9DWQPA pic.twitter.com/RnMDFa2uMk— RTÉ News (@rtenews) April 22, 2020
The World Health Organization has supported setting up a quarantine site in Kuwait University Hospital in Sana'a, which contains 30 beds, ventilators and oxygen tanks.
The World Food Programme currently feeds more than 12 million Yemenis a month.
The WFP's Senior Economist, Arif Husain, said: "Covid-19 is potentially catastrophic for millions who are already hanging by a thread. It is a hammer blow for millions more who can only eat if they earn a wage.
"Lockdowns and global economic recession have already decimated their nest eggs. It only takes one more shock, like Covid-19, to push them over the edge. We must collectively act now to mitigate the impact of this global catastrophe."