Reducing spread of nukes a high priority: Obama

WASHINGTON: Satellite photos released show Pakistan has expanded two sites crucial to its nuclear program as part of an effort to bolster the destructive power of its atomic arsenal, a US arms control institute said. US President Barack Obama said it is "absolutely imperative" that the United States take the lead in reducing the spread of nuclear weapons.

"It is absolutely imperative that America takes leadership working with, not just our Russian counterparts, but countries all around the world to reduce and ultimately eliminate the dangers that are posed by nuclear weapons," the president said after an Oval Office meeting with former secretaries of state George P. Shultz and Henry Kissinger, former Defense Secretary William Perry and former Sen. Sam Nunn of Georgia.

Obama mentioned possible steps to "lock down loose nuclear weapons," including revitalizing the Nuclear Nonproliferation Treaty, making progress on a Comprehensive Test Ban Treaty and working with Russia to reduce dependence on nuclear weapons.

Russia and the U.S. have the world's largest nuclear stockpiles.

"We are going to be pushing this as one of our highest priorities, to take specific steps, measurable steps, verifiable steps, to make progress on this issue, even as we keep a long-term perspective and a long-term vision about what can be achieved," Obama told reporters. "And we can think of no better advisers, counselors, and partners in this process than the four gentlemen who joined us here today."