There is an "urgent need" to help developing countries adapt to impacts of climate change, UK Climate Change Minister Ian Pearson has said.
The talks hope to bridge the divide between rich and poor nations
Nations were experiencing environmental changes as a result of greenhouse gases already in the atmosphere, he told MPs.
He said he was hopeful that an action plan and funding would be agreed at a climate summit in Africa next month.
But Mr Pearson added that the talks on the Kyoto Protocol were unlikely to deliver new global emission targets.
He made his comments while giving evidence to the Commons Environmental Audit Committee's inquiry into how the UN Kyoto Protocol will progress after the current period for emission targets ends in 2012.
Mr Pearson said that it was helpful that the talks on the protocol were being hosted by an African government.
"Climate change is a huge issue when it comes to Africa. There will certainly be a strong focus on adaptation in Nairobi because it is one of the most pressing issues facing countries in sub-Saharan Africa today," he said.
"A large number of the countries that did not sign up to Kyoto are very small emitters and they are not a big part of the problem.
"But they are going to be affected by the climate change that is already in the (atmospheric) system," the minister told committee members.
The two-week summit will look at what progress has been made by the legally binding agreement that requires industrial nations to cut their emissions by an average of 5.2% from 1990 levels by the period 2008-2012.
Delegates will also consider what system should be adopted when the current period ends.
Earlier this month, the UK government co-hosted a climate conference in Mexico for the world's top 20 polluting nations.
The two-day informal gathering brought together ministers from G8 industrialised countries and developing nations to try to reach a consensus on the issue.
When asked by Labour MP David Chaytor whether the meeting undermined the UN negotiations, Mr Pearson disagreed.
"The key thing was to continue to build international consensus on the science and practical actions in terms of what needs to be done," he told the committee.
However, he said it would be very difficult to get ministers from 189 nations at the Nairobi summit to reach an agreement on what should happen after 2012.
A number of nations, including the US, the world's biggest polluter, favour technological advances rather than targets to reduce emissions.
"I would love to say that I feel confident that everyone is going to Nairobi with the expectation that there is going to be a long-term international agreement, but I do not think that is going to be the case," Mr Pearson conceded.
"What we can realistically expect... is to hopefully agree an adaptation work programme and an adaptation fund which will be important issues for developing countries."