The Obama administration today underlined the need for discussions on a Fissile Material Cut-off Treaty, which will halt production of plutonium and highly enriched uranium for weapons purposes, and also asked countries to sign the test ban treaty.

"The US seeks to begin negotiations as soon as possible on a Fissile-Material Cut-off Treaty with appropriate monitoring and verification provisions," Secretary of State Hillary Clinton said.

A universal FMCT will halt production of plutonium and highly enriched uranium for weapons purposes, capping the size of existing arsenals and reducing the risk of terrorist groups gaining access to them, she said.

In her speech on nuclear non-proliferation at the US Institute of Peace, Clinton said: "We must do more than reduce the numbers of our nuclear weapons. We must reduce the role they play in our security."

Arguing that it is the time for a fresh look at the views on the role of the United States' nuclear weapons arsenal, Clinton said the US can't afford to continue relying on "recycled Cold War thinking".

"We are sincere in our pursuit of a secure, peaceful world without nuclear weapons. But until we reach that point of the horizon where the last nuclear weapon has been eliminated, we need to reinforce the domestic consensus that America will maintain the nuclear infrastructure needed to sustain a safe and effective deterrent without nuclear testing," she said.

Clinton said the United States would go for a robust nuclear-complex budget in 2011 besides supporting a new stockpile-management program that would focus on sustaining capabilities.

"This is what the military leaders charged with responsibility for our strategic deterrent need to defend our country," she said.

Reiterating the commitment of the Obama administration towards Comprehensive Test Ban Treaty (CTBT), Clinton said for almost two decades and over four successive administrations, the US has observed a moratorium on nuclear testing.

"So we are already honoring the fundamental obligation of the treaty," she said.

"A test-ban treaty that has entered into force will allow the US and others to challenge states engaged in suspicious testing activities, including the option of calling on-site inspections to be sure that no testing occurs anywhere," she said.

CTBT ratification, she argued, would also encourage the international community to move forward with other essential nonproliferation steps.

"And make no mistake. Other states rightly or wrongly view American ratification of the CTBT as a sign of our commitment to the nonproliferation consensus," she said.