Washington, April 6 (Inditop.com) President Barack Obama hopes to use next week’s nuclear security summit to clearly spell out how to secure world’s nuclear material so it does not fall into the hands of terrorists or dangerous states.

“Our expectation is not that there’s just some vague, gauzy statement about us not wanting to see loose nuclear materials,” he said in an interview Monday with the New York Times ahead of the summit that would bring 47 world leaders, including Prime Minister Manmohan Singh, together.

“We anticipate a communique that spells out very clearly, here’s how we’re going to achieve locking down all the nuclear materials over the next four years.”

Obama said the new American nuclear strategy to be unveiled Tuesday would substantially narrow the conditions under which the US would use nuclear weapons, even in self-defence.

But, Obama said he would make an exception for “outliers like Iran and North Korea” that have violated or renounced the nuclear non-proliferation treaty (NPT).

With the new approach, Obama sees the US leading by example in efforts to reduce the proliferation of nuclear weapons and eventually make them obsolete, Obama told the Times, signalling a clear break with his predecessors on the issue.

Instead, threats could be dealt with by “a series of graded options,” he said, combining old and new conventional weapons. “I’m going to preserve all the tools that are necessary in order to make sure that the people are safe and secure,” Obama told the Times.

“We are going to want to make sure that we can continue to move towards less emphasis on nuclear weapons,” he said, to “make sure that our conventional weapons capability is an effective deterrent in all but the most extreme circumstances.”

White House officials cited by the Times said the new strategy would include the option of reconsidering the use of nuclear retaliation against a biological attack, if the development of such weapons reached a level that made the US vulnerable to a devastating strike.

The new strategy, known as the Nuclear Posture Review, differs considerably from the one President George W. Bush published in early 2002, just three months after the Sep 11, 2001 attacks, the Times noted. Bush, too, argued for a post-Cold War rethinking of nuclear deterrence, reducing American reliance on those weapons.

But Bush’s document also reserved the right to use nuclear weapons “to deter a wide range of threats,” including banned chemical and biological weapons and large-scale conventional attacks.

Obama’s strategy abandons that option, except if the attack is by a nuclear state, or a non-signatory or violator of the NPT.

India, Pakistan and Israel, three states with nuclear weapons have refused to sign and North Korea renounced the treaty in 2003. Iran remains a signatory, but the United Nations Security Council has repeatedly found it in violation of its obligations.