WASHINGTON: Rewriting the nation’s nuclear strategy, the White House said the spread of atomic weapons to rogue states or terrorists was a worse threat now than the nuclear Armageddon feared during the Cold War.

In announcing the shift, the White House is moving swiftly on multiple fronts, although it is not clear how far and how fast the rest of the world is ready to follow.

In releasing the results of an in-depth nuclear strategy review, President

Obama said his administration would narrow the circumstances in which the United States might launch a nuclear strike, that it would forgo the development of new nuclear warheads, and that it would seek even deeper reductions in the United States and Russian arsenals.

His defence secretary, Robert M Gates, said the focus would now be on terror groups such as al-Qaeda as well as North Korea’s nuclear build-up and Iran’s nuclear ambitions.

“For the first time,

preventing nuclear proliferation and nuclear

terrorism is now at the

top of America’s nuclear agenda,” Obama said, distancing his administration from the decades-long US focus on arms competition with Russia.

Obama’s announcement set the stage for his trip to Prague, the Czech capital, on Thursday to sign an arms-reduction agreement with Russia.

And it precedes a gathering in Washington on Monday of government leaders from more than 40 countries to discuss improving safeguards to keep nuclear bombs from falling into the hands of terrorists.

Two leading Senate voices on nuclear strategy, Arizona Republicans John McCain and Jon Kyl, criticised the Obama policy’s

restrictions on using nuclear arms to retaliate against a chemical or biological attack.

“The Obama administration must clarify that we will take no option off the table to deter attacks against the American people and our allies,” they said in a joint statement.

His current push for arms-control initiatives is designed to strengthen international support for strengthened non-proliferation efforts.

“Given al-Qaeda’s continued quest for nuclear weapons, Iran’s ongoing nuclear efforts, and North Korea’s proliferation, this focus is appropriate and, indeed, an essential change from previous” policy, Gates said.

In presenting the results of the administration’s policy review, Gates said a key aim was to reduce the role of nuclear weapons in US defence strategy.