External Affairs Minster S M Krishna today again pressed upon Australia to lift ban on uranium sale to India. He insisted that nuclear power is necessary for energy starved developing countries.Krishna raised the issue in his meeting with Australian counterpart Kevin Rudd in Melbourne today. Rudd acknowledged India's clean record on nuclear proliferation, but maintained it was Australia's national policy to not sell the yellow metal to NPT non-signatories. Rudd said the issue, however, has not damaged ties between the countries. Krishna had yesterday taken up the issue with Australia's Resource, Energy and Tourism Minister Martin Ferguson.Addressing a joint press conference here along with the visiting Krishna, Rudd acknowledged that India has not been responsible for a single act of nuclear weapons proliferation anywhere in the world.Rudd said there is a huge amount underway in the Australia-India relationship at the political, security and economic levels. He said, there's sufficient ballast in this relationship to deal with areas of periodic disagreement as there are in all relationships.Commenting on the issue, Krishna said he has pleaded with the Australian government to change the policy, stressing that nuclear energy as a clean energy source was crucial to the rising energy demands of India. He said, if you have to have clean energy, then according to India the only option is to have nuclear energy, and if you have to have nuclear energy, then you certainly need uranium.On the question of the security of Indian students in Australia, Rudd gave his full assurance to his counterpart.