The Barack Obama administration was to release its new nuclear strategy on Tuesday just ahead of a major atomic security conference to be hosted by the US next week, the White House said Monday.

White House spokesman Robert Gibbs said the new document, which is expected to stress non-nuclear deterrent capabilities, will also build momentum before the two-day nuclear security summit which opens on April 12.

A senior administration official said last month that President Barack Obama planned "dramatic reductions" in the country's arsenal of nuclear weapons as part of his administration's sweeping review.

The review "will point to dramatic reductions in the stockpile, while maintaining a strong and reliable deterrent through the investments that have been made in the budget," the official said.

It will also "point to a greater role for conventional weapons in deterrence" and rule out the need to develop low-yield "bunker-buster" nuclear weapons for penetrating underground targets, said the official, speaking on condition of anonymity.

The strategy, dubbed the "Nuclear Posture Review," will be published a day before Obama heads to Prague to sign a replacement for the Strategic Arms Reduction Treaty (START) with Russian President Dmitry Medvedev.

In order to pursue a key foreign policy aim of halting nuclear proliferation, Obama has committed the United States -- the only country ever to unleash an wartime atomic bomb -- to a series of nuclear arms cuts.

In April 2009, Obama promised in a landmark speech in Prague to work towards a world without nuclear weapons. But he has admitted however he does not expect to see that goal reached during his lifetime.

The policy review "will be an important step forward in pursuing the goal of reversing the spread of nuclear weapons and seeking a world without them," the official said.

The secretive review of the country's nuclear strategy, which has not been carried out since 2002, has been delayed, bogged down by apparent divisions within the administration. It was initially due to be released in December.

But experts have predicted that despite calls from anti-nuclear lobbyists the new strategy will be modest and will not represent a major overhaul of the current policy.

In February, The New York Times reported that the administration had rejected proposals that the United States declare that it would never be the first to use nuclear weapons.

The new strategy will also come just two days between Obama and Medvedev sign a new treaty promising to slash their stockpiles of long-range nuclear warheads by a third.

After months of intense negotiations, the pair sealed what Obama called "the most comprehensive arms control agreement in nearly two decades."

Armed with the replacement for the START treaty and a new nuclear review, Obama will host leaders from around the world Monday for a two-day nuclear security summit in Washington.

From April 12-13 they will discuss the prevention of acts of nuclear terrorism, and steps that can be taken to secure vulnerable nuclear materials.

Among world leaders attending will be Chinese President Hu Jintao under global pressure to swing behind imposing fresh sanctions on Iran for its continued refusal to rein in its suspect nuclear program.

French President Nicolas Sarkozy and German Chancellor Angela Merkel will also take part in the summit, expected to be attended by high-level officials from nuclear-armed neighbors, India and Pakistan.

The United States has said it currently has some 2,200 nuclear warheads, while Russia is believed to have about 3,000.

The administration is also pushing the US Senate to ratify the Comprehensive Test Ban Treaty, which would ban all nuclear tests, whether military or civilian.