With US President Barack Obama presiding, the UN Security Council is expected to give a big political boost to long-stalled efforts to move toward a world without nuclear weapons. Diplomats said the UN's most powerful body will vote unanimously Thursday on a draft resolution calling for stepped up efforts to prevent the spread of nuclear weapons, promote disarmament and "reduce the risk of nuclear terrorism." Obama is the first US president to chair a summit-level meeting of the council and he will be joined by 14 other world leaders, US deputy ambassador Alejandro Wolff said. Obama aides see the resolution that will be adopted at the meeting as an endorsement of the president's entire nuclear agenda, as laid out in his April speech in Prague in which he declared his commitment to "a world without nuclear weapons." The president called in that speech for the slashing of US and Russian nuclear arsenals, adoption of the treaty banning all nuclear tests, an international fuel bank to better safeguard nuclear material, and negotiations on a new treaty that "verifiably" ends the production of fissile materials used to make atomic weapons. He also strongly backed the Nuclear Nonproliferation Treaty, or NPT, which requires signatory nations not to pursue nuclear weapons in exchange for a commitment by the five nuclear powers to move toward nuclear disarmament. States without nuclear weapons are guaranteed access to peaceful nuclear technology to produce nuclear power. All those measures are included in the draft resolution. In its opening paragraph, the draft reaffirms the council's commitment "to seek a safer world for all and to create the conditions for a world without nuclear weapons." Arms control advocates say such elements are interconnected. Some nations might eventually reject the limitations of the Non-Proliferation Treaty, for example, if the US and other nuclear powers don't abide by that treaty's requirement to move toward disarmament by reducing their arsenals, or if they reject the test ban. Also Thursday, the US rejoins a biannual conference designed to win more support for the treaty banning all nuclear bomb tests. Secretary of State Hillary Rodham Clinton was scheduled to help kick off that UN session, uniting foreign ministers and other envoys from more than 100 nations that have ratified or at least signed the 1996 treaty. It represents the first US participation since 1999. Former Democratic Sen. Sam Nunn, a leading arms-control advocate who heads the Nuclear Threat Initiative, a Washington-based group designed to fight the global spread of nuclear materials, called the draft before the Security Council "an excellent resolution." Nunn said Obama's message is that "we are in a race between cooperation and catastrophe." The draft resolution does not mention any country by name but it reaffirms previous Security Council resolutions that imposed sanctions on Iran and North Korea for their nuclear activities. It does not call for any new sanctions. The draft "expresses particular concern at the current major challenges to the nonproliferation regime that the Security Council has acted upon." It also calls on all countries that are not parties to join the treaty "to achieve its universality at an early date," and in the interim to comply with its terms. The major countries that are not members of the NPT are India and Pakistan, which have conducted nuclear tests, and Israel which is believed to have a nuclear arsenal. Obama has invited Queen Noor of Jordan, a founder of an international initiative to eliminate nuclear weapons which includes current and former senior officials from nuclear powers, to sit in the Security Council chamber for the vote and speeches. She said in an interview that the resolution "would be a historic step toward an international consensus, and it would pave the way for governments to start working to achieve this goal." "I believe that world leaders have come to recognize that the only way to eliminate the nuclear threat is to eliminate all nuclear weapons, and it is urgent to begin making this vision a reality," said Noor, the widow of King Hussein.