United Nations Secretary-General Antonio Guterres in an undated photo. Guterres is urging countries to revitalize the Treaty on the Non-Proliferation of Nuclear Weapons, as experts caution that a nuclear arms race may be imminent. (UN Photo/Jean-Marc Ferre)
Diplomats are meeting at the United Nations headquarters in New York for a high-stakes review of the world’s primary nuclear arms control agreement, amid warnings that global stockpiles are growing again after decades of decline.
The conference marks the 11th review of the Treaty on the Non-Proliferation of Nuclear Weapons, a pact in force since 1970 that aims to curb the spread of nuclear weapons, promote disarmament and support peaceful nuclear cooperation.
Held every five years, the gathering comes at a moment of heightened geopolitical tension and renewed competition among nuclear powers.
“We need to breathe life into the treaty once more,” U.N. Secretary-General Antonio Guterres said in a statement Monday, warning that progress toward eliminating nuclear weapons has stalled as trust between nations erodes.
The meeting, which is expected to span several weeks, is the first in decades to take place while the total number of nuclear warheads is increasing, the U.N. said.
That reverses a long post-Cold War trend, when the United States and Russia reduced their arsenals following the collapse of the Soviet Union in 1991.
The shift comes as military spending continues to climb. Global defense expenditures reached $2.8 trillion in 2025, a 2.9% increase from the previous year, according to data released this week by the Stockholm International Peace Research Institute.
Do Hung Viet, Vietnam’s ambassador to the United Nations and president of the conference, said global nonproliferation efforts face growing uncertainty in the current climate.
“This is not just another conference,” Do said. “The stakes are very high because the danger of a nuclear war is seen and felt much more concretely these days. A nuclear arms race is looming.”
Nine countries possess nuclear weapons, with the United States and Russia accounting for nearly 90% of the global inventory, according to the institute.
China has been rapidly expanding its arsenal, while other nuclear-armed states are also upgrading their capabilities, the report said.
Russia’s war in Ukraine, concerns over Iran’s nuclear activities and North Korea’s continued weapons development all threaten to divide conference participants.
Early disagreements surfaced even before formal talks began, with the United States and several allies opposing Iran’s nomination to a leadership role in the conference. Russia criticized the objection as politicizing the process.
The last two review conferences ended without consensus, underscoring the difficulty of reaching agreement among countries with sharply differing security priorities.
Still, diplomats say the stakes extend far beyond procedural outcomes. With emerging technologies such as artificial intelligence and quantum computing adding new risks to nuclear command and control systems, failure to strengthen safeguards could have far-reaching consequences, they say.
The conference is scheduled to run through May 22.
