By Alex Kirby
BBC News Online environment correspondent
The UK environment minister, Elliot Morley, has sought to calm fears the government will shortly give the go-ahead to genetically modified crops.
The government will evaluate each crop individually
Mr Morley said there were still several issues to be settled, and the UK could not let GM crops be grown commercially.
He told journalists the UK would give no blanket approval for GM varieties, but would judge each crop on its own.
But it is clear the government is close to making an announcement on GM crops in the UK, probably in early March.
Mr Morley was speaking at a news conference in the Malaysian capital, Kuala Lumpur, where he was attending a meeting of the UN's Convention on Biological Diversity.
He said: "We haven't finalised for example our co-existence rules, we haven't addressed the issue of whether there may be a liability issue.
"There is still uncompleted work in the UK. We are not yet in a position for GM commercialisation.
"There will be no blanket approval as far as the UK is concerned in relation to GM crops.
"Each application will be dealt with on its own merits."
Mr Morley also insisted the UK was not arguing for GM crops as a way to feed the world.
He said: "It is not for us to advocate or force upon other countries GM technology.
"We have no strategy in terms of being advocates for GM technology internationally. That's not a matter for the government."
Dr Tewolde Egziabher, who spoke on behalf of the African Group at the convention's meeting, is director-general of Ethiopia's Environmental Protection Authority, and in effect his country's environment minister.
A sceptic on the uses of GM crops, he told the news conference: "A single technology does not constitute development.
"There is no evidence that GM varieties produce better or more than their non-GM counterparts. They only bring in new vulnerabilities."
Mr Morley's careful choice of words seems designed to take the heat out of the GM debate in advance of the government's announcement.
Reports last week said it would give the green light to the commercial growing in Britain of genetically modified maize.
But while ministers may make a policy statement as early as next week, they have not yet decided finally what they will say.
Among the issues they have to resolve is "co-existence" - whether they are confident it is possible to grow GM varieties in the UK without the risk of contaminating conventional and organic crops.