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

Even the most modest option now under consideration would be a 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 around 1,000 to 1,100, 700 to 800, or 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.

Obama often has talked of 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.

Stephen Young, senior analyst at the Union of Concerned Scientists, which favors nuclear arms reductions, said Tuesday, “The administration is absolutely correct to look at deep cuts like this. The United States does not rely on nuclear weapons as a central part of our security.”

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.

The administration last year began considering a range of possible future reductions below the levels agreed in the New START treaty with Russia that took effect one year ago. Options are expected to be presented to Obama soon. The force levels he settles on will form the basis of a new strategic nuclear war plan to be produced by the Pentagon.

The U.S. already is on track to reduce to 1,550 deployed strategic nuclear warheads by 2018, as required by New START. As of last Sept. 1, the United States had 1,790 warheads and Russia had 1,566, according to treaty-mandated reports by each. The treaty does not bar either country from cutting below 1,550 on its own.

Those who favor additional cuts argue that nuclear weapons have no role in major security threats of the 21st century, such as terrorism. A 2010 nuclear policy review by the Pentagon said the U.S. nuclear arsenal also is “poorly suited” to deal with challenges posed by “unfriendly regimes seeking nuclear weapons,” an apparent reference to Iran.

It is unclear what calculus went into each of the three options now under consideration at the White House.

The notion of a 300-weapon arsenal is featured prominently in a paper written for the Pentagon by a RAND National Defense Project Institute analyst last October, in the early stages of the administration’s review of nuclear requirements. The author, Paul K. Davis, wrote that he was not advocating any particular course of action but sought to provide an analytic guide for how policymakers could think about the implications of various levels of nuclear reductions.

Davis wrote that an arsenal of 300 weapons might be considered adequate for deterrence purposes if that force level was part of a treaty with sound anti-cheating provisions; if the U.S. deployed additional non-nuclear weapons with global reach, and if the U.S. had “hypothetically excellent,” if limited, defenses against long- and medium-range nuclear missiles.

In 2010, three Air Force analysts wrote in Strategic Studies Quarterly, an Air Force publication, that the U.S. could get by with as few as 311 deployed nuclear weapons, and that it did not matter whether Russia followed suit with its own cuts.

New U.S. cuts could open the prospect for a historic reshaping of the American nuclear arsenal, which for decades has stood on three legs: submarine-launched ballistic missiles, ground-based ballistic missiles and weapons launched from big bombers like the B-52 and the stealthy B-2. The traditional rationale for this “triad” of weaponry is that it is essential to surviving any nuclear exchange.

As recently as last month the administration said it was keeping the triad intact under current plans, while also hinting at future cuts to the force. In the 2013 defense budget submitted to Congress on Monday, the administration proposed a two-year delay in the development of a new generation of ballistic missile submarines that carry nuclear weapons. That would save an estimated $4.3 billion over five years.

In congressional testimony last November, the Pentagon’s point man on nuclear policy, James N. Miller, would not say what options for force reductions the administration was considering. Republican Rep. Michael Turner, chairman of the House of Representatives’ Armed Services Committee strategic forces subcommittee, unsuccessfully pressed Miller for key details about his policy review. As recently as last month Turner said in an interview that he feared the administration was bent on cutting the force.

In his written testimony at a Nov. 2 hearing chaired by Turner, Miller made it clear that the administration was making a fundamental reassessment of nuclear weapons requirements. In unusually stark terms he said the critical question at hand was “what to do” if a nuclear-armed state or nonstate entity could not be deterred from launching an attack.

“In effect, we are asking: what are the guiding concepts for employing nuclear weapons to deter adversaries of the United States, and what are the guiding concepts for ending a nuclear conflict on the best possible terms if one has started?” he said.

Nuclear stockpile numbers are closely guarded secrets in most states that possess them, but private nuclear policy experts say no countries other than the U.S. and Russia are thought to have more than 300. The Federation of American Scientists estimates that France has about 300, China about 240, Britain about 225, and Israel, India and Pakistan roughly 100 each.

Since taking office Obama has put heavy emphasis on reducing the role and number of nuclear weapons as part of a broader strategy for limiting the global spread of nuclear arms technology and containing the threat of nuclear terrorism. That strategy is being put to the test most urgently by Iran’s suspected pursuit of a nuclear bomb.