A weapons trainer talks to U.S. officials about an inert non-nuclear B53 training weapon during an event commemorating the dismantling of the final B53 nuclear bomb in Amarillo, Texas on Oct. 25, 2011. (The Amarillo Globe News, Roberto Rodriguez/Associated Press)

The Obama administration is weighing options for sharp new cuts to the U.S. nuclear force, including a reduction of up to 80 per cent in the number of deployed weapons, The Associated Press has learned.

Even the most modest option now under consideration would be an historic and politically bold disarmament step in a presidential election year, although the plan is in line with President Barack Obama's 2009 pledge to pursue the elimination of nuclear weapons.

No final decision has been made, but the administration is considering at least three options for lower total numbers of deployed strategic nuclear weapons cutting to: 1,000 to 1,100; 700 to 800, and 300 to 400, according to a former government official and a congressional staffer. Both spoke on condition of anonymity in order to reveal internal administration deliberations.

The potential cuts would be from a current treaty limit of 1,550 deployed strategic warheads.

A level of 300 deployed strategic nuclear weapons would take the U.S. back to levels not seen since 1950 when the nation was ramping up production in an arms race with the Soviet Union. The U.S. numbers peaked at above 12,000 in the late 1980s and first dropped below 5,000 in 2003.

Options for new round of cuts

Obama has often cited his desire to seek lower levels of nuclear weapons, but specific options for a further round of cuts had been kept under wraps until the AP learned of the three options now on the table.

A spokesman for the White House's National Security Council, Tommy Vietor, said Tuesday that the options developed by the Pentagon have not yet been presented to Obama.

The Pentagon's press secretary, George Little, declined to comment on specific force level options because they are classified. He said Obama had asked the Pentagon to develop several "alternative approaches" to nuclear deterrence.

The U.S. could make further weapons reductions on its own but is seen as more likely to propose a new round of arms negotiations with Russia, in which cuts in deployed weapons would be one element in a possible new treaty between the former Cold War adversaries.

Even small proposed cuts are likely to draw heavy criticism from Republicans who have argued that a smaller nuclear force would weaken the U.S. at a time when Russia, China and others are strengthening their nuclear capabilities. They also argue that shrinking the American arsenal would undermine the credibility of the nuclear "umbrella" that the United States provides for allies such as Japan, South Korea and Turkey, who might otherwise build their own nuclear forces.