A delegation of former ministers from South Sudan has told the Archbishop of Canterbury Justin Welby about the growing humanitarian crisis and sense of hopelessness gripping their conflict-ravaged country. The group was led by Rebecca Garang, a former presidential advisor, minister and widow of John Garang, the founder of the Sudanese People’s Liberation Movement. Mrs Garang and her colleagues painted a bleak scene of growing poverty and hunger.

Archbishop Justin heard how very few people could now afford to buy food, although it is available. Much of the population has not been paid for months and the economy has been hit by hyperinflation. Many had been reduced to eating wild foods, such as water lilies and fish caught from swamps. People were becoming so weak that they were dying from relatively minor illnesses.

The Archbishop described the situation as heartbreaking, saying that he couldn't remember hearing about such a terrible situation. It reminded him of what was happening in in the Democratic Republic of Congo. “It is the worst in Africa for a very long time," he said. "It is beyond description.”

The delegation also described the sense of hopelessness. People were just sitting around, waiting, because they didn’t know what the next day would bring. Young people were losing faith in their homeland. They were resigned to becoming refugees and living overseas – and didn’t see themselves going back because there was no future.

The meeting took place in Nairobi and came as the US issued a statement expressing frustration with the lack of progress towards a peace agreement. Washington said it would be re-examining the assistance programmes it is providing for South Sudan.

The Archbishop was in Nairobi for the regional Primates’ Meeting of CAPA (the Council of Anglican Provinces in Africa). In a tweet afterwards, he said it had been a privilege to meet Mama Rebecca Garang and her fellow leaders. He called for people to pray for peace which was so urgently needed.

“Pray for God’s will to be done and for the horrendous humanitarian suffering of the people in South Sudan to come to and end,” he said.

• This article was updated on 14 May 2018