The UN Food and Agriculture Organisation on Wednesday asked for $3.5 million (2.6 million euros) to help 235,000 people on the brink of starvation on the border between Sudan and South Sudan.

"Food availability in Blue Nile and South Kordofan is forecast to be significantly reduced following renewed fighting between government troops and the Sudan People's Liberation Movement-North (SPLM-N)," FAO said.

The Food and Agriculture Organisation said the fighting had disrupted the major crop season with household food stocks already at their lowest.

It said the two regions were two of the main sorghum-producing areas in Sudan, adding that next month's harvest "is expected to generally fail."

"In South Kordofan, people fled at the start of the planting season, so were unable to sow seeds. In Blue Nile, fighting erupted later in the season so seeds were planted but people were forced to abandon their crops," FAO said.

FAO said international aid agencies had been barred from Blue Nile while a small team of its local staff was on the ground in South Kordofan. It said they had distributed seeds and tools to 20,000 vulnerable households.