US President Barack Obama, chairing a special UN Security Council meeting he called to strengthen the Nuclear Non-Proliferation Treaty, succeeded in unanimously passing a resolution on Thursday that is aimed in part at increasing pressure on Iran and North Korea to rein in their nuclear programs.The move came after American meetings with Russian officials and, separately, with permanent Security Council members late Wednesday, in which the US expressed satisfaction that those countries were contemplating stronger measures against Iran.Obama has made reducing nuclear weapons and the security of nuclear materials a priority of his presidency and used a rare bully pulpit at the UN Security Council to stress his commitment to the issue, as part of a broad approach that the US hopes will make it easier to curb rogue regimes like those in Teheran and Pyongyang pursuing nuclear capabilities at odds with the treaty.On Wednesday, Obama noted that most of his meeting with Russian President Dmitry Medvedev was devoted to Iran, and that while both countries prefer to deal with Teheran diplomatically, "I think we also both agree that if Iran does not respond to serious negotiations and resolve this issue in a way that assures the international community that it's meeting its commitments, and is not developing nuclear weapons, then we will have to take additional actions."He underscored, "Serious additional sanctions remain a possibility."Medvedev, for his part, said, "Sanctions rarely lead to productive results. But in some cases sanctions are inevitable."The comments follow a decision by Obama to drop controversial plans by the previous administration to deploy long-range missile defenses in former Soviet satellite states, to which Moscow strenuously objected, instead placing less objectionable systems to defend against shorter-range missiles from Iran.Though White House officials have largely denied any link between the policy change and hopes that Russia will be more forthcoming on sanctions, Medvedev called the decision a "reasonable" one that takes Russian concerns into consideration."We are ready to continue this work with our US colleagues in this direction, as well as with our European colleagues," he said of missile defense.Obama and Medvedev also affirmed their commitment to renew the treaty that will see both countries continue to reduce their nuclear arsenals.Similarly, US Secretary of State Hillary Clinton on Thursday made America's first appearance in 10 years at a conference aimed at reducing nuclear testing. And emerging from her P5+1 meeting - with Russia, China, Britain, France and Germany - she announced a consensus on approaching Iran with a "dual track" strategy of engagement and pressure.Clinton reported that she and her counterparts agreed that the talks with Iran scheduled for next Thursday need to address the nuclear issue, even though Teheran has said the topic was off the table."Iran should come to the talks on October 1 ready to engage in serious and substantive discussions with a sense of urgency and a review of the practical steps that need to be taken on the nuclear issue," she said, adding that further steps would be determined depending on the meeting's outcome."We are committed to this dual-track policy," she stressed. "No one should underestimate our intention to follow through on either or both of these tracks."In his comments to the Security Council Thursday morning, Obama said that he wasn't stigmatizing any country, but then proceeded to name names."We've made it clear that the Security Council has both the authority and responsibility to determine and respond as necessary when violations of this treaty threaten international peace and security," he said. "That includes full compliance with Security Council resolutions on Iran and North Korea."Thursday's resolution says only that the Security Council shares "particular concern at the current major challenges to the nonproliferation regime that the Security Council has acted upon, demands that the parties concerned comply fully with their obligations under the relevant Security Council resolutions, and reaffirms its call upon them to find an early negotiated solution to these issues."The resolution doesn't explicitly mention Israel, India or Pakistan, countries that are not signatories to the pact, but which have or are believed to have nuclear weapons.But it does call for all countries to sign the Non-Proliferation Treaty and for the negotiation by member-states of a treaty on the nuclear disarmament of countries, and urges "all other states to join in this endeavor."Israeli officials have indicated that aside from the specific points in the resolution, they are pleased by the statement the US is making on the issue and the message that it sends out about dealing with nuclear weapons.Obama himself, in opening the meeting - only the fifth summit-level parley in UN history - said it was a sign of the priority he placed on the issue."I called for this one so that we may address at the highest level a fundamental threat to the security of all peoples and all nations: the spread and use of nuclear weapons," he explained. "Your presence is an affirmation of the importance of the subject matter to be discussed."The nonbinding resolution calls for stricter export controls on nuclear material, refraining from nuclear testing and extending international oversight to nuclear materials sold to countries, even if they later pull out of the treaty, among other measures.Obama also noted how Thursday's effort echoes his April 5 Prague speech, where he laid out his vision for a world free of nuclear weapons.However, in his Security Council comments on Thursday, he spoke of the tragic and destabilizing risk of a nuclear bomb exploding in New York, Moscow, Beijing, London or Paris, whereas in Prague he had included Tel Aviv, Islamabad and Mumbai in that list, cities in countries whose conflicts have frequently roiled the United Nations.It remains to be seen whether most of the diplomatic activity on nuclear issues on Wednesday and Thursday will have teeth and actually be put into effect. Russia and China, among others, have previously made encouraging statements, only to backtrack on sanctions and other issues.But the positive momentum on America's agenda pleased US officials in New York this week, and helped bolster Obama as he has faced questions at home and abroad over his ability to get results from international players.