"The crisis is expected to escalate significantly in the months ahead. The Norwegian Government is therefore allocating a further $63 million to humanitarian efforts in South Sudan," Børge Brende said on the eve of a conference for international donors to the country in Oslo.
The Nordic country has been one of the largest sponsors of the South Sudan, which became the world's youngest country when it gained its independence from the north in 2011.
Fighting broke out in the country last September, three months after Riek Machar, one of the leading figures of the Nuer people, was sacked as deputy President by President Salva Kiir, a senior figure in the Dinka people.
The United Nations has warned of a widespread famine in South Sudan if fighting between the government and rebel groups does not stop. It says 3.7 million people -- more than a third of the population -- are at risk of starvation in the world's youngest nation, where has thousands of people have been killed and more than 1.2 million forced to leave their homes.
The UN says it needs $1.8 billion to fund humanitarian aid through to the end of March 2015, and only $536 million has been secured so far.
"If the conflict continues, half of South Sudan's 12 million people will either be displaced internally, refugees abroad, starving or dead by the year's end," UN Secretary General Ban Ki-moon said last week.
Norway, which sent $17 million to South Sudan at the beginning of the year, will on Tuesday host a conference to try to raise funds and find ways to improve the delivery of humanitarian assistance there. The event will be co-chaired by Brende and UN humanitarian chief Valerie
"Tens of thousands of people have already died in South Sudan even if they still haven't taken their last breath," said Liv Tørres, head of the non-governmental organisation Norwegian People's Aid. "It's a terrible thing to say, but that does not make it any less true. For many it's already too late. There isn't enough food produced and stored away
before the rainy season begins."
Here's an interview with Riek Machar about the impending conflict in December last year.