The United Nations Security Council held a special summit Thursday to discuss nuclear non-proliferation and disarmament. It was an extraordinary meeting on another fronts. President Obama became the first U.S. president to chair a UN Security Council Summit and the meeting marked only the fifth Summit-level meeting of the Council in its 63 years of existence.

The Security Council unanimously passed a resolution aimed at shoring up the international commitment to limiting the spread of nuclear weapons. While the resolution did not mention Iran and North Korea, several world leaders including President Obama referred to the nations in their remarks.

The U.S.-drafted resolution called for further efforts to achieve “a world without nuclear weapons.” But critics of the resolution said it failed to include mandatory provisions that would have required nuclear weapons states to take concrete disarmament steps. The resolution also lacked any call on nuclear states to halt production of fissile materials for nuclear weapons.