The President hailed the agreement as a landmark in halting the spread of nuclear weapons and beginning multilateral disarmament.
"The historic resolution we just adopted enshrines our shared commitment to a goal of a world without nuclear weapons," he said. "We now face proliferation of a scope and complexity that demands new strategies and new approaches."
But forceful statements from other leaders on the need to act against Iran following the vote threatened to upstage the special meeting.
Nicolas Sarkozy, the French president, came close to mocking his American counterpart for the good intentions, which Mr Obama had heralded as an "historic" step towards nuclear abolition, even though it set no specific targets or fresh mandates.
"We live in a real world not a virtual world," the Frenchman told the 15-member council. "And the real world expects us to take decisions.
"President Obama dreams of a world without weapons ... but right in front of us two countries are doing the exact opposite.
"Iran since 2005 has flouted five security council resolutions. North Korea has been defying council resolutions since 1993.
"I support the extended hand of the Americans, but what good has proposals for dialogue brought the international community? More uranium enrichment and declarations by the leaders of Iran to wipe a UN member state off the map," he continued, referring to Israel.
The sharp-tongued French leader even implied that Mr Obama's resolution 1887 had used up valuable diplomatic energy. (continues here)