The Obama Administration is taking a number of steps not only to stop the spread of nuclear weapons, but also to secure loose nuclear materials, the White House has said.
"He's (the US President, Barack Obama) taking a series of steps in this area to stop the spread of nuclear weapons, to secure loose nuclear materials, and to pursue the ultimate goal of a world without nuclear weapons," Ben Rhodes, Deputy National Advisor for Strategic Communications told reporters in Tokyo where Obama is travelling right now.
Obama is expected to speak on this issue when he addresses some 1500 people in Tokyo on Saturday, he said.
Meanwhile, State Department in Washington said the US at present do not have any specific concern coming from Pakistan on the nuclear proliferation front.
"I think we are always concerned about the possibility of the proliferation of nuclear weapons and nuclear materials. We feel confident that the command and control of nuclear weapons in Pakistan is secure. We don't have any specific concerns about proliferation per se specifically from Pakistan," State Department spokesman, Ian Kelly, told reporters at a news briefing.