Failure to agree a common way forward at the International Whaling Commission (IWC) annual meeting is "unfortunate", says Japan's minister attending.
In an interview with BBC News, Ms Yasue Funayama said Japan had had to "sweat and bleed" to bring agreement closer.
Other countries had insisted on an end to whaling in the Antarctic, which was not justified by science, she said.
But Japan would continue working within the IWC, said the vice-minister of agriculture, forestry and fisheries.
A two-year process aimed at agreeing a package that sought to reform the regulation of whaling for the next 10 years concluded on Wednesday here with countries reporting they could not reach agreement on a number of fundamental points.
Ms Funayama suggested that all the effort put in by various parties ought to have made a deal possible.
"I feel it is extremely unfortunate because we have been making much effort up until now; we had made substantial compromises, and we had made so much effort to try to narrow the differences," she told BBC News.
"We felt this was a negotiation, we felt that Japan also had to sweat and bleed, and that is the stance we have been taking in these negotiations."
The most contentious element of the compromise package was the extent to which Japan was prepared to scale down its whaling in the Southern Ocean over the 10-year period - with the EU, Australia and the Latin American bloc keen it be brought down to zero.
"Of course, if it was indeed the case that zero had to be the number for proper management of the whale stock - if it was in a critical situation - then of course Japan would agree that it had to be brought down to zero," said Ms Funuyama.
"However, we do have evidence that the whale stock is sustainable if it is contained under a certain level of catch, and therefore we fail to understand why it has to be brought down to zero."
The answer given by Japan's opponents is that its fleet ought to leave the Southern Ocean not because the current level of hunting is unsustainable, but because the area has been declared a whale sanctuary.
Ms Funayama declined to say how low Japan had offered to go from its current self-awarded maximum quota of 935 minke whales per year.
But a number of delegates from countries opposed to commercial whaling that were heavily engaged in the talks said a number as low as 150 per year could have been secured, if Japan had received the right signals from the EU and the Latin American bloc.
They also said Japan had been prepared to accept other key elements of the package, such as the requirement that whalemeat be restricted for domestic consumption only.
Iceland and Norway had also been prepared to accept further cuts in their catches than the original proposal drawn up by the IWC chairman and vice-chairman had suggested, sources said.
Matters of perspective
As the meeting closed, delegates and organisations debated whether anything had been achieved - and in particular, whether continuing the status quo represented a success or a failure.
"Members of the IWC have missed an important opportunity to take steps towards ending commercial whaling," said Junichi Sato, whaling campaigner with Greenpeace Japan.
"The sum total of what has been achieved with the decision to reflect for another year is that under the status quo the blood of 1,500 more whales will be needlessly spilled by Japan, Iceland and Norway.
"Japan has not negotiated in good faith with IWC members, nor is it serving the interests of its own people by continuing to waste taxpayers' money on a morally, financially and scientifically bankrupt whaling programme in the Southern Ocean whale sanctuary."
The claim that Japan was to blame for failure in the talks - widely promulgated by environment groups - was dismissed by Sir Geoffrey Palmer, the former New Zealand Prime Minister who played a leading role in diplomacy here.
"I was in the middle of this, and I think that's absolutely false," he said.
"The luxury about NGO positions is they don't actually know what is going on.
"The truth of the matter is there was considerable flexibility shown on both sides - just not quite enough."
WWF pointed out that conservation achievements were made, in particular praising the decision to investigate the impacts of oil and gas exploration and development in the Arctic, which the group describes as "critical in the wake of the disastrous oil spill in the Gulf of Mexico".
The IWC will meet next year, despite suggestions that it should not; and so far, all member countries appear to be backing the institution, despite the lack of agreement on the main issue here.