LONDON Tue Mar 17, (bdnews24.com/Reuters) - The world must find ways to help non-nuclear states obtain civilian nuclear power to meet energy needs and tackle the growing threat of climate change, British Prime Minister Gordon Brown will say on Tuesday. Brown will tell a London nuclear energy conference that Iran is key to proving whether nuclear producers and non-producers can share enriched uranium peacefully to power their economies as the world tries to wean itself off fossil fuels. "We have to create a new international system to help non-nuclear states acquire the new sources of energy they need," Brown will say, according to extracts from his speech. "Because, whether we like it or not, we will not meet the challenges of climate change without the far wider use of civil nuclear power." The two-day conference brings together more than 100 representatives from 35 countries as well as well as experts from the International Atomic Energy Agency (IAEA), the nuclear industry, academics and legislators. Delegates come from countries considering establishing a nuclear programme as well as states that have well-developed civil nuclear industries. The conference fits into Britain's strategy of helping countries that commit to peaceful use of nuclear power while taking a "zero tolerance" approach to the spread of nuclear weapons. FUEL GUARANTEE Britain says it is ready to give a guarantee to countries that fear their supply of nuclear fuel could be disrupted for political reasons if they rely on outside suppliers. Under its Nuclear Fuel Assurance programme, Britain pledges to supply nuclear fuel cycle services to countries committed to peaceful use of nuclear power if their supply is disrupted. Speakers at the conference, most of which is closed to the media, include IAEA Deputy Director-General Yury Sokolov, Khaled Toukan, chairman of Jordan's Atomic Energy Commission and officials from Germany and the Netherlands. The conference will also hear a pre-recorded message from IAEA Director-General Mohamed ElBaradei. The United States, Britain and four other powers have offered Iran civil nuclear cooperation as part of a package of incentives to try to persuade Tehran to stop uranium enrichment, which the West fears is aimed at building a nuclear bomb. Iran says it only wants nuclear power for peaceful purposes and has pledged to press on with its programme. "Iran is a test case for this new philosophy of the right to civil nuclear power with sanctions for rule breakers," Brown will say. "Iran's current nuclear programme is unacceptable. Its refusal to play by the rules leads us to view its nuclear programme as a critical proliferation threat." He will urge Iran to "take advantage of the international community's willingness to negotiate, including (US) President Obama's offer of engagement, rather than face further sanctions". The recent surge in energy prices, dwindling resources and the need to meet climate change goals is giving a new lease of life to nuclear power. Britain is set to build a new generation of nuclear power plants.