Tony Blair has called for an "open-minded" debate on the future of nuclear power in the UK.
Mr Blair said he was not 'pre-empting' the debate
The prime minister said concerns over possible fossil fuel shortages and global warming were "too strong for anybody reasonably to ignore".
But the UK's targets for using more renewable sources, such as wind and wave power, were "very ambitious".
But Mr Blair told his monthly news conference he was not "pre-empting the debate at all" over nuclear energy.
The government has not ruled out building more atomic power stations to help it meet carbon emission targets and plug the energy gap created by the closure of ageing plants.
Mr Blair said the nuclear industry needed a "decision and a framework".
He added that it was "responsible to start this debate and have it in a very open way" and to "take what decisions we think are right for the country".
Trade Secretary Alan Johnson has said government will bring forward proposals for nuclear power next year to allow a public debate on the issue.