Millions of people globally, including in some African countries, risk dying from conflict-driven hunger, with the Covid-19 pandemic and climate change making the situation worse, UN Secretary General Antonio Guterres has warned.

More than 30 million people in zones such as the Sahel, the Horn of Africa, South Sudan, Yemen and Afghanistan are "just one step away" from a declaration of famine.

"Without immediate action, millions of people will reach the brink of extreme hunger and death," Mr Guterres told the UN Security Council during a meeting on food and security.

In South Sudan, Mr Guterres said 60% of the population were “increasingly hungry.”

He said the Democratic Republic of the Congo experienced “the world's largest food crisis last year, with nearly 21.8 million people facing acute hunger between July and December".

The UN chief also expressed concern about the situation in Tigray, Ethiopia, where the harvest season has been disrupted by insecurity and violence, and hundreds of thousands of people could be experiencing hunger.

Oxfam International Executive Director Gabriela Bucher said people in these worst areas "are not starving - they are being starved."

"In today's world, famine is human-made. And if it is caused by us, that means it must be stopped by us too," Linda Thomas-Greenfield, the US ambassador to the UN, said

Meanwhile UN agencies were appealing for $5.5bn (£3.9bn) in emergency mobilisation for those most affected by hunger, Mr Guterres said.