North Korea on Wednesday refused South Korea's offer of flood relief aid, crushing emerging hopes for a thaw in tense relations between the two Koreas.
The North changed its position only two days after expressing its intention to accept Seoul's proposal for assistance made on Sept. 3.
The Unification Ministry said it sent a list of items for shipment Tuesday including 10,000 tons of flour, 3 million packets of noodles, and medical equipment.
The North sent a letter on Wednesday afternoon saying, "Such an assistance is not necessary," according to the ministry.
"It is regrettable. But we will continue with general humanitarian assistance for the North regardless of political and military situations," a ministry official said.
Accepting Seoul's offer on Monday, the North requested the types and quantity of items to be shipped.
Pyongyang is believed to want rice, cement and heavy equipment for reconstruction work, which Seoul worries that the regime may divert for military and other unintended uses.
The North's letter is thought to indicate an attempt to pressure the South, with a sentence saying that "incidents similar to those of last year must not occur."
Last year, the ministry planned a relief programme worth 5 billion won (S$5.52 million), which chiefly consisted of medical kits and necessities including nutritious meals for infants and toddlers, snacks and ramen.
The deal was tossed out after the South rejected the North's demand for a larger package to include repair machines.
In 2010, the ministry agreed to a 10 billion won package including 5,000 tons of rice, 10,000 tons of cement and 3 million packets of instant noodles.
It shipped all but 7,000 tons of cement as the project came to a halt in the wake of the North's artillery shelling on a South Korean border island in the West Sea that year.
Observers had been keen on the developments of flood aid as it raised hopes for the two governments holding the first contact since the North's defiant rocket launch in April.
The ministry in charge of inter-Korean affairs has been calling for talks on the resumption of reunions of separated families and tours to Mount Geumgang.
If the agreement had been materialized, it would have marked Seoul's first official handout in two years, though civic groups have been allowed to provide relief.
The ministry approved last week an application from World Vision, a Christian aid group, to send 500 tons of flour to North Korean flood victims.
On Wednesday, it approved another 500-ton flour package by Join Together Society Korea, a non-profit relief organisation.
The North's state news agency reported that floods in June and July left 569 people dead or missing and swept away or inundated 65,280 hectares of farmland.
Two powerful typhoons, which pummeled the peninsula at the end of last month, killed another 176, forced 220,000 out on the streets and damaged at least 50,000 hectares of cropland.