UNITED NATIONS (AP) — Secretary-General Ban Ki-moon pledged Friday to do everything in his power to build on the historic U.N. summit chaired by President Barack Obama and advance the goal of a nuclear weapons-free world.

Ban said he will be pressing for progress on disarmament and nuclear nonproliferation at a number of major events this year.

“Today, there is a new window of opportunity in disarmament and nonproliferation,” he said. “Last year, we saw several encouraging developments. This year, we have much on which to build — and a heavy agenda going forward.”

Ban’s comments to a closed-door meeting with the heads of the International Atomic Energy Agency and the organizations overseeing the treaty banning chemical weapons and the nuclear test ban treaty were released by the United Nations.

The U.N. chief said he will build “on the historic Security Council summit last September” which unanimously approved a U.S.-sponsored resolution — with Obama presiding — aimed at halting the spread of nuclear weapons and ultimately eliminating them.

The sweeping strategy endorsed by the U.N.’s most powerful body urged action on a long list of proposals before the international community and in various ways reaffirmed support for the Nuclear Nonproliferation Treaty. The 1968 accord, considered the cornerstone of global nonproliferation efforts, aimed to prevent the spread of atomic arms beyond the five original weapons powers — the U.S., Russia, Britain, France and China.

The council resolution called for negotiation of a treaty banning production of fissile material for nuclear bombs and establishment of internationally supervised nuclear fuel banks, to keep potential bomb material out of more hands — both items on Obama’s agenda. It also urged states to ratify the Comprehensive Test Ban Treaty, the 1996 pact banning all nuclear bomb tests, another Obama goal.

Ban said he will promote the universality of all treaties, encourage the Security Council “to provide political support for the full implementation of treaty obligations and the strengthening of the treaty organs,” and attend a number of conferences to advance nonproliferation efforts.

“I pledge to continue to do everything in my power to advance the goal of a world free of weapons of mass destruction,” he said.

Later this month, Ban said he will attend the Conference on Disarmament, a 65-nation U.N. body in Geneva, which will hopefully start talks on a Fissile Material Cutoff Treaty banning production of nuclear bomb material.

The conference was deadlocked for 12 years trying to open talks on a treaty, a stalemate resulting in part from opposition by former President George W. Bush’s administration. Obama’s reversal of the U.S. position in an April speech led the conference to adopt an agenda for talks in May, but resistance from Pakistan — a nuclear-armed nation — has stalled further progress.

In early February, Ban will attend the Global Zero Summit in Paris, which is expected to bring hundreds of international leaders to the French capital to discuss a step-by-step plan for the phased, verified elimination of nuclear weapons. He will then attend the 46th Munich Security Conference which will address the major security challenges including nuclear proliferation.

The secretary-general said he also will attend the summit on Nuclear Security that Obama is hosting in Washington in April to bring government leaders together to consider cooperative efforts to track and protect weapon-usable materials and to safeguard against nuclear terrorism.

These events “will help generate momentum” for the five-year review of the Nuclear Nonproliferation Treaty at U.N. headquarters in New York in May, Ban said.

The last review conference in 2005 was unable to agree on an agenda until nearly three weeks after it started — a major factor in its failure. By contrast, delegates agreed on an agenda in May. Zimbabwe’s U.N. Ambassador Boniface Chidyausiku, who chaired the preparatory meeting, credited Obama for reversing Bush’s policy.

Chidyausiku said then that there wasn’t enough time to agree on recommendations to the conference that balanced the three pillars of the treaty — disarmament by the nuclear powers, preventing the proliferation of nuclear weapons, and ensuring the peaceful use of nuclear energy — but he was optimistic about progress at the review conference in May.

“The differences — they were not major,” Chidyausiku said. “With time, we could have done it.”