North Korea has refused to receive flood relief supplies from South Korea after checking details of the aid on offer, a government official in Seoul said Wednesday.
The North this week responded to Seoul's offer, made following devastating floods in June and July, by asking the South to present more details of its proposal.
On Tuesday the South sent a list of aid items it was offering its neighbour, including 10,000 tonnes of flour, instant noodles and medicine.
But the following day the North suddenly changed its stance, saying it would not accept "such aid", a ministry official told AFP.
The official added that the list of supplies had not included rice -- a key issue in an earlier refusal of aid.
Last year Pyongyang spurned an offer of emergency supplies from South Korea and demanded rice and cement instead. South Korea refused, citing suspicions that it would be diverted to the military.
The South made its aid offer last week -- the first such proposal since ties with Pyongyang sank into a deep freeze following the death of the North's leader Kim Jong-Il last December.
Tensions were further fuelled by a joint US-South Korea military exercise last month that the North denounced as a provocative rehearsal for war.
The impoverished North is grappling with the after-effects of floods in June and July that killed 569 people and inundated 65,280 hectares (161,310 acres) of crop-bearing land, according to official figures from Pyongyang.
The South's government stopped its annual major food and fertiliser shipments to the North after President Lee Myung-Bak's conservative administration took office in early 2008.
Humanitarian aid by civic groups has been allowed into the country, although modest in scale.
North Korea suffers chronic food shortages, with the situation exacerbated by floods, droughts and mismanagement. Hundreds of thousands died during a famine in the mid- to late-1990s.