Speaking at a U.N. conference on disarmament Monday, Secretary-General António Guterres warned that international arms control mechanisms are collapsing, and called on the United States and Russia to recommit to the Intermediate-Range Nuclear Forces Treaty—known as the INF—and to extend the New START Treaty before it expires in 2021.

Secretary-General António Guterres: “States are seeking security, not in the proven collective value of diplomacy and dialogue, but in developing and accumulating new weapons. And the situation is particularly dangerous as regards nuclear weapons. … We simply cannot afford to return to the unrestrained nuclear competition of the darkest days of the Cold War.”

Guterres also called on negotiating parties at the North Korean summit in Hanoi this week to take concrete steps toward a denuclearization deal.

Meanwhile, Russian state television aired a map of U.S. military facilities that would become targets in the event of a nuclear strike. The report said that a hypersonic missile being developed by Russia would be able to hit the targets in less than five minutes. Last week, Russian President Vladimir Putin said he was ready for a “Cuban missile-style” crisis if the U.S. provoked the nuclear power.