Image caption The Nagoya conference aimed to secure a future for the endangered natural world

Conservation groups have expressed concern that a major UN conference on nature protection is stalling, with some governments accused of holding the process hostage to their own interest.

Their warning comes halfway through the UN Convention on Biological Diversity (CBD) meeting in Nagoya, Japan.

During negotiations some countries have proposed weaker rather than stronger targets for protection, they say.

Some developing countries say the West is not meeting their concerns.

"The most optimistic assessment is that we have not gone far towards a deal," said Muhtari Aminu-Kano, senior policy advisor with BirdLife International.

"The main reason is that there are several delegations that are not showing the political will needed to break the deadlock here," he told BBC News.

"It's your usual story - it's people putting their national interests far above the importance of biodiversity."

Having failed to meet the target set in 2002 of significantly reducing the rate of biodiversity loss by 2010, the draft agreement before this meeting contains a set of 20 targets.

But there is fundamental division between those demanding tough pledges, such as ending biodiversity loss by 2020, and those who argue this is not possible.

Another draft clause calls for a 100-fold increase in international financing on biodiversity, which would be raised principally in industrialised nations and primarily spent in the developing world.

'Shocking and pitiful'

While the main priority for Western nations is to secure tough targets for protecting plants and animals and the habitat they need, developing countries are in general more concerned about international finance, and about an agreement on fair and equitable access to the Earth's natural genetic resources.

Guide to biodiversity Biodiversity is the term used to describe the incredible variety of life that has evolved on our planet over billions of years. So far 1.75m present day species have been recorded, but there maybe as many as 13m in total. The term "biodiversity" refers to diversity of ecosystems, species and genes. In wetlands, for example, you might find different types of fish, frogs, crabs and snails; and within each species, differences in the genes which determine disease resistance, diet and body size. Research shows that ecosytems containing more variety are more productive and more robust. Biodiversity loss affects most of the major branches of life on Earth. Amphibians and corals are among some of the most threatened. Rising human populations, habitat loss, invasive species and climate change all take their toll. Around half of the planet's natural environments had been converted for human use by 1990. The IUCN projects that a further 10-20% of grass and forest land could be converted by 2050. Deforestation represents one of the most serious threats to biodiversity. The map shows the extent of the planet's remaining frontier forests - which exist in a state untouched by human interference - and the original extent of forest cover. The rising population and economic growth mean that natural resources are used at less and less sustainable rates. WWF calculates that by 2050, humanity's resource use would need two-and-a-half Earths to be sustainable. BACK {current} of {total} NEXT

Such an agreement - known as access and benefit sharing (ABS) - was prescribed when the CBD came into existence 18 years ago, but successive attempts to negotiate it have failed.

Developing nations - where most of the planet's unexplored genetic resources lie - want an equitable share in the profits generated when Western companies develop drugs or other products from plants or anything else that came from their territory.

Some - notably within the African bloc - are insisting that such an agreement should be retrospective, which would imply Western companies would have to pay compensation for products already on the market.

"Some countries are holding everything hostage to resolving ABS," said Sue Lieberman, director of international policy with the Pew Environment Group.

"I'm not saying that's not important, but if you look at the status of the marine environment, it's shocking and pitiful to think there might be no progress here at all.

"We're particularly disappointed in Brazil."

Some governments, she said, were arguing that the CBD should not discuss conservation on the high seas, while others were proposing that only 1% of the world's coastal waters should be protected.

The existing global target for marine protection is 10%.

Echoes of Copenhagen?

Although Brazil has a special place in the history of environmental protection, having hosted the 1992 Earth Summit, Dr Lieberman has not been alone here in pointing to its substantial presence and robust negotiating style as being an impediment to progress.

It's hard to see how we can enhance and stimulate more sustainable use of biodiversity if the rules on benefit sharing are not agreed Braulio Dias, Brazilian delegation

Braulio Dias, secretary of biodiversity and forests with the Brazilian environment ministry and a key member of its national delegation, said a lack of movement on its concerns could mean blocking tougher protection.

"We see this as a big negotiating package; we can't commit ourselves to ambitious targets if we don't see an equivalent commitment to the means to meet those targets, and on the other agreement to finalise negotiations on the ABS protocol," he told BBC News.

"It's hard to see how we can enhance and stimulate more sustainable use of biodiversity if the rules on benefit sharing are not agreed."

The ABS negotiations, like some of the other components here, have seen through long and arduous sessions - and will continue over the weekend, given the lack of agreement.

But Ahmed Djoghlaf, CBD executive secretary, said things were moving.

"There has been tremendous progress on ABS, with more than 20 articles adopted - and after one week of negotiations, this is tremendous progress," he told reporters.

"I've seen references to [the climate summit in] Copenhagen. There's no comparison with Copenhagen at all - the spirit is there, the spirit of conciliation, the spirit to continue discussing."

Most countries are sending environment ministers to the final three days of the meeting, and some observers are hopeful about the extra momentum that may create.

There is also hope that the arguments made here about the economic value of biodiversity, contained in the final report from the UN-backed Economics of Ecosystems and Biodiversity (Teeb) project, will persuade governments that meeting the targets on the agenda here would create wealth rather than damaging it.

"It's ironic that at this meeting there's been the release of the Teeb report, which has wonderful information about the economic benefits from conservation of the natural systems and the risks of losing those benefits to human well-being as a whole," noted Andrew Rosenberg, senior vice-president for science and knowledge with Conservation International.

"In a meeting where that's coming up, to make the argument that 'we can't afford it' is really depressing."